key: cord-0753351-d70al2la authors: Menon, Shalini; Mathew, Manna Rachel; Sam, Sonia; Keerthi, K.; Kumar, K. Girish title: Recent advances and challenges in electrochemical biosensors for emerging and re-emerging infectious diseases date: 2020-08-25 journal: J Electroanal Chem (Lausanne) DOI: 10.1016/j.jelechem.2020.114596 sha: 5b1d590376bf7f5df3a8f8f3965338c97ca5cdc8 doc_id: 753351 cord_uid: d70al2la The rise of emerging infectious diseases (EIDs) as well as the increase in spread of existing infections is threatening global economies and human lives, with several countries still fighting repeated onslaught of a few of these epidemics. The catastrophic impact a pandemic has on humans and economy should serve as a reminder to be better prepared to the advent of known and unknown pathogens in the future. The goal of having a set of initiatives and procedures to tackle them is the need of the hour. Rapid detection and point-of-care (POC) analysis of pathogens causing these diseases is not only a problem entailing the scientific community but also raises challenges in tailoring appropriate treatment strategies to the healthcare sector. Among the various methods used to detect pathogens, Electrochemical Biosensor Technology is at the forefront in the development of POC devices. Electrochemical Biosensors stand in good stead due to their rapid response, high sensitivity and selectivity and ease of miniaturization to name a few advantages. This review explores the innovations in electrochemical biosensing based on the various electroanalytical techniques including voltammetry, impedance, amperometry and potentiometry and discusses their potential in diagnosis of emerging and re-emerging infectious diseases (Re-EIDs), which are potential pandemic threats. The inherent risk of EID's is that the introduction of a pathogen into a community drastically decreases the percentage of healthy individuals in a society which would leave an ireversible social and economic stain. The number of potential pathogens worldwide is on the rise, while the research and development (R&D) resources are minimal [1] . Currently, medical R&D models do not account for the application of enhanced disease detection/ prevention kits to epidemics that are intermittent or unpredictable, especially when they occur in countries with minimal investment in healthcare infrastructure [1] . When faced with the challenge of a novel pathogen, the situation becomes even graver. The international community has recognized the need for innovation to improve our capacity to respond to emerging threats and the need to plan for potential epidemic outbreaks with an emerging R&D paradigm. The need for R&D in this area to be prioritized cannot be stressed enough, through which R&D could also be instrumental in planning the response to an outbreak. In its 2007 study, the World Health Organization cautioned that infectious diseases are emerging at an alarming rate [2] . There have been about 40 infectious diseases reported since the 1970s, including Middle East respiratory syndrome (MERS), severe acute respiratory syndrome (SARS), ebola, chikungunya, swine flu, avian flu, Zika and most recently Novel Coronavirus Disease (COVID-19) [2] . The potential for these diseases to spread rapidly and have catastrophic global impact has high probability due to the increasing international travel, population explosion in developing/ under-developed countries and ever increasing proximity with wild animals. Re-EIDs are those caused by pathogens that are raising health concerns for a significant proportion of the population after being dormant for a while. Schistosomiasis is re-emerging in Egypt; Ebola hemorrhagic fever is making a come back in West Africa and Legionellosis had been reported in Philadelphia [3] . to become drug-resistant, while the mosquito host has also developed tolerance to pesticides [3] . Whooping cough (pertussis) and Diphtheria have also shown to be prevalent in communities [3] . Identification, monitoring and treatment of diseases are the primary objectives of all public health programs [4] . Effective methods of identification are paramount in preventing or mitigating the spread of a virus before the consequences make an impact to the society. Hence, the global market for diagnoses of infectious diseases is projected to increase substantially in the coming years as per a report obtained from various sources which includes expert interviews, secondary literature, market and market analysis (Fig. 1 ) [5] . Healthcare facilities usually utilize cell culture systems that require a complex of cell separation processes from their normal (in vivo) setting and subsequent growth in an artificially (in vitro) created environment with different nutrients and antibiotics [6] . Thereby pathogen recognition is visually determined based on the observed distinct growth patterns [6] . However, cell culture is increasingly losing its role and its relative importance in the diagnosis of human diseases as this technique requires expertises and trained personnel, sophisticated instruments and is also time consuming [7] . The need of the hour is the clinical diagnosis for early and successful detection and treatment. Consequently, molecular-related approaches, including nucleic acid sequencing and polymerase chain reaction (PCR) have taken center stage as methods of diagnosis to substitute strategies dependent on cell culture. Although J o u r n a l P r e -p r o o f Journal Pre-proof they are more sensitive, precise and reliable in detection of microorganisms with reduced diagnosis time (1-4 hours), they do have certain shortcomings in comparison with cell culture [7] . Problems that restrict the application of molecular-related approaches to routine diagnosis includes false positive and false negative results and lack of uniformity in molecular testing [8] . Moreover there are possibilities for wrongly interpreting and differentiating between a disease and an infection as the existence of nucleic acid does not necessarily indicate the presence of viable species [8] . Most of the technologies dicusssed are out of reach to majority of the world's population since they are complex, centralized and need skilled technicians to operate. The need for portability, cost reduction and ease of use is thus largely appreciable, particularly in the case of neglected diseases. Biosensing technique is a promising diagnostic technology which has gained popularity in recent decades due to its numerous benefits [9] . Biosensors have aided in revolutionizing the treatment of various health problems since its inception, five decades ago [9] . Their effectiveness in clinical management, and characteristics like specificity, rapidity and responsiveness are considered key in initiating early diagnosis and therapy [9] . The advancements made in emerging techniques like nanotechnology and microfluidics, coupled with the identification of biomarkers would boost the efficiency of healthcare sector. Transducer integration in biomaterials has allowed for the development of interfaces capable of producing signals -aptly discussed as biosensors [10] . Biosensors, which are bio-electromechanical systems, can be classified based on transducer form, label and general configuration [10] . Biosensors are designed to suit specific functionalities and affinities. Recognition of analytes can often contribute to a transition in three-dimensional structure that is signal, which is transmitted to the signal processor through the transducer [12] . The signal is further amplified and noise is separated out before relevant information is retrieved. Electrochemical biosensing techniques will be compared to the most widely used conventional methods (Cell culture systems, immunofluorescence (IF) method and molecular approach) for the diagnosis of infectious diseases. Table 1 summarizes the advantages and disadvantages of electrochemical biosensors over these popular conventional methods. Scientific community has been indebted to voltammetric biosensors as it is able to provide the information of a biological system by converting it into an electronic signal. They belong to a class of electroanalytical sensing methodologies, where the current generated is monitored between the working electrode and a counter electrode upon sweeping potential between working electrode and a reference electrode [30] . In voltammetry, the heterogeneous electron transfer takes place at the methods) and demand for the targets to be redox active in the given potential range [33] make the systems complicated than other electroanalytical techniques. [35] [36] [37] [38] [39] , DNAs [40, 41] , proteins or antibodies (depending on the mode of biorecognition) are also immobilized for the selective recognition. The mechanism behind the immobilization of recognition elements clearly depends on the physical and chemical properties of the transducer and the environment in which the system operates. Although, physical interactions such as hydrophobic or electrostatic are simple, it causes negative impact on the analytical performance, stability and reproducibility of the sensor [33] . Another effective mode of immobilization is the covalent tethering of receptor surface to transducer exposed carboxyl or amine units. Among this, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) coupling is a popular method for receptor immobilization, wherein a covalent bridging occurs between amine groups and carboxyl groups via the amine nucleophilic attack on a generated active ester intermediate [33] . Affinity binding approaches like receptor biotinylation and its induced high affinity for preimmobilised streptavidin, is another more functional and stable potential mode for receptor immobilization [33] . Since all biological processes are dependent on pH, it is important to put more concern on the pH of the buffer, where the studies are executed. The pH of the blood must be maintained at 7.4 and hence researchers have done most of the studies in this physiological pH. with a limit of detection 4.7 nM [46] . They used gold screen-printed electrode for the detection and prior to detection, the probe DNA was immobilized on its surface. During the detection step, biotinylated target DNA strand gets hybridized with the probe DNA and gets interacted with streptavidin-alkaline phosphatase enzyme. The oriented, nanocoaxial electrodes in array format [54] . The linear range was obtained as 10 ng/mL -1 µg/mL and the limit of detection was found to be 2 ng/mL, which is comparable to the optical ELISA approach. The fabricated sensor array proved to be an excellent platform for diagnosis of infectious cholera toxin in the POC scenario. Recently, SARS-CoV-2 or COVID-19 outbreak has emerged as a global pandemic and resulting as a serious public health issue all over the world. Mahari et al. Electrochemists have been familiar with the Electrochemical Impedance Spectroscopic (EIS) technique for over a century [57] . The fact that EIS can be used effectively for the label free detection makes it a powerful tool in biosensing applications [4] . The occurrence of a bio-recognition process is always followed by some changes in various physical and chemical properties at the electrode electrolyte interface, and EIS technique makes use of the changes in charge transfer resistance (Rct) or interfacial capacitance to mark the biochemical changes occurring at the sensor surface [4, 57] . Unlike other electrochemical methods such as cyclic voltammetry which involves large amplitude perturbations, small amplitude perturbation in EIS makes it a non-destructive technique [58] . In spite of being an ideal method for understanding dynamics of biochemical reactions, EIS technique suffers from several challenges. One among them is the sensitivity of the so developed label free biosensor [4, 58] . Studies reveal that sensitivity of these sensors is lower compared to the biosensors that utilize labels. Though labelling can enhance selectivity and sensitivity, it consumes extra time, involves difficult sample handling and is also expensive [59] . Journal Pre-proof Another major challenge to be addressed is whether the technique works good in real samples such as blood serum, where there is a significant amount of non-target molecules. [60] . Now a great deal of effort has been done by researchers in an attempt to improve the sensitivity by modifying electrodes with nanocomposites, conducting polymers, metal nanoparticles etc. [61, 62] . In simpler terms impedance can be regarded as a resistance to the flow of current in an electrical circuit. Basically, information from impedance measurement Recently, Chowdhury and Park reported another promising work [78] . They developed an ultrasensitive impedance immunosensor for hepatitis E virus (HEV) detection. Notable significance is that the sensor was able to attain sensitivity Literature clearly reveals that the era of electrochemical biosensors was established on amperometric and potentiometric transducer platforms [80] [81] . An amperometric glucose biosensor itself was the stepping stone towards the development of cost effective, reliable, rapid and handy POC diagnostic devices, which then created a revolution in medical diagnosis [82] . The current-time response of electrooxidation/reduction of an electroactive species, at an optimal potential is monitored in amperometry [83] . The current generated will be proportional to the concentration of the electroactive species and the excellent selectivity in detection offered by this potentiostatic technique made it the widely used one in chemical sensor development [84] . In addition, wide concentration range of detection and low-cost instrumentation J o u r n a l P r e -p r o o f Journal Pre-proof of amperometric technique has made it a preferred one for sensor developers [85] . Minimization of charging current (current needed to apply potential) which affects the detection limit is also an advantage of amperometry [32] . Indeed, the blend of selectivity provided by amperometry and the specificity in binding offered by biorecognition elements have led to the successful development of numerous highly sensitive and reliable biosensors so far [86] . In amperometric biosensors, specific bioreceptor-target binding produces amperometric signal either directly or indirectly. Charge transfer from electron rich label attached to the target molecule can produce direct signals. On the other hand, indirect signalling is possible through redox processes catalysed by enzyme labels on the target molecule. Natural polymers like glycans also act as a bioreceptors that selectively react with certain proteins to give indirect amperometric signals. Conducting polymers and nanomaterials have been also incorporated in these biosensors to enhance the immobilization of the recognition element and thereby stability and sensitivity [87] [88] . Simplicity in design of an amperometric detector paves possibilities for miniaturisation of these biosensors as mentioned earlier [89] . However, signal reduction due to interference from sample matrix exists as a challenge of amperometric enzyme based sensors [90] . Fig. 6 is a general schematic representation of an amperometric biosensor. analysis of infectious diseases. However, in the current situation of the emergence of deadly mutated pathogens, it is expected that the research in the near future will be focussing on the excellent specificity offered by genosensing for rapid bedside testing. The working principle behind potentiometric sensors is that, the potential difference between working and reference electrodes varies directly with the concentration of the analyte under study, at zero current flow [100] . Ion selective, gas sensitive electrodes and Field Effect Transistors (FET) are the usually employed transducers in potentiometric sensors, which are selected, based on the nature of the species under study. This tuning of the working electrode can enhance the selectivity and sensitivity [101] and which in combination with other key features of potentiometric technique such as non-invasion, cost effectiveness and sensitivity have led to the development of many biosensors important in biomedical analysis [102, 103] . Since fabrication of biosensors to POC devices have been the prime goal among researchers, FET based potentiometric sensors have gained very much attention recently, which might be due to FET's built-in potential for miniaturisation [104] . Ease of fabrication, rapid response and highly sensitive label-free detection by FET has also amplified the interest of researchers for this transducer platform [105] . FET is a semiconductor which can detect both human H1N1 and avian H5N1 influenza viruses in nasal mucus [109] . Rapid detection in the wide concentration range 10 0.5 to 10 8.5 TCID 50 /ml was made possible by functionalizing the gate terminals with two different sialic acid containing glycans that recognize human and avian viruses respectively. Feasibility of the assay was also successfully demonstrated by connecting it to a smartphone. All the measurements were carried out at physiological pH (pH 7.4). The remarkable stability and sensitivity exhibited by glycan-immobilized FET biosensor over an antibody-immobilized (antibodies are the widely used recognition elements with FET) [110] one is also discussed. In addition, Goswami and co-workers developed an aptamer based extended gate FET biosensor for malaria biomarker, plasmodium J o u r n a l P r e -p r o o f Journal Pre-proof falciparum glutamate dehydrogenase (Pfgd) [105] . The extended gate was used for increasing the sensitivity and biocompatibility if the FET. Anti-Pfgd aptamer was immobilized on an interdigitated gold microelectrode, which was attached to gate terminal of the FET. The net charge produced on the electrode surface due to aptamer-Pfgd binding led to detection of Pfgd in human serum samples in the linear range 100 fM to 10 nM with a limit of 48.6 pM within a minimal response time (~ 5 s). The developed device has a very good potential for POC settings as well (Fig. 9 ). Blueprint for R & D preparedness and response to public health emergencies due to highly infectious pathogens Baylor college of medicine, Emerging infectious diseases Understanding Emerging and Re-emerging Infectious Diseases The role of biosensors in the detection of emerging infectious diseases Cell culture, technology: Enhancing the culture of diagnosing human diseases Biosensors Applied to Diagnosis of Infectious Diseases -An Update Gene Specific DNA Sensors for Diagnosis of Pathogenic Infections Simultaneous determination of guanine and adenine in the presence of uric acid by a poly(para toluene sulfonic acid) mediated electrochemical sensor in alkaline medium Pathogen detection: A perspective of traditional methods and biosensors Redox-active monolayers self-assembled on gold electrodes-effect of their structures on electrochemical parameters and DNA sensing ability Poly(Amino Hydroxy Naphthalene Sulphonic Acid) Modified Glassy Carbon Electrode; An Effective Sensing Platform for the Simultaneous Determination of Xanthine and Hypoxanthine A voltammetric sensor for acetaminophen based on electropolymerized-molecularly imprinted poly(oaminophenol) modified gold electrode Simultaneous Voltammetric Determination of Acetaminophen and Its Fatal Counterpart Nimesulide by Gold Nano/L-Cysteine Modified Gold Electrode Role of cell culture for virus detection in the age of technology Methods for rapid virus identification and quantification PCR and Infectious Diseases Advanced pathology techniques for detecting emerging infectious disease pathogens, Advanced Techniques in Diagnostic Microbiology The impact of molecular approaches to infectious disease diagnostics Disease-related detection with electrochemical biosensors: A review Electrochemical biosensors for pathogen detection Review-Chemical and Biological Sensors for Viral Detection Minireview: Trends in Optical-Based Biosensors for Point-Of-Care Bacterial Pathogen Detection for Food Safety and Clinical Diagnostics Applications and Perspectives of Biosensors for Diagnostics in Infectious Diseases Burnham-marusich, crossm Diseases : Past, Present, and Future Synthetic Biology-Based Point-of-Care Diagnostics for Infectious Disease Laboratory Techniques in Electroanalytical Chemistry Voltammetric determination of mercury(II) Electrochemical biosensors Electrical biosensors and the label free detection of protein disease biomarkers Electro-oxidation of Dopamine at CoNP-pAHNSA modified electrode: A sensitive approach to its determination Comparison of two fabricated aptasensors based on modified carbon paste/oleic acid and magnetic bar carbon paste/Fe3O4@ oleic acid nanoparticle electrodes for tetracycline detection An aptasensor for tetracycline using a glassy carbon modified with nanosheets of graphene oxide Dualaptamer based electrochemical sandwich biosensor for MCF-7 human breast cancer cells using silver nanoparticle labels and a poly (glutamic acid)/MWNT nanocomposite Designing and fabrication of a novel sensitive electrochemical aptasensor based on poly (L-glutamic acid)/MWCNTs modified glassy carbon electrode for determination of tetracycline Impedimetric PSA aptasensor based on the use of a glassy carbon electrode modified with titanium oxide nanoparticles and silk fibroin nanofibers Self-assembled monolayer of SH-DNA strand on a magnetic bar carbon paste electrode modified with Fe 3 O 4 @Ag nanoparticles for detection of breast cancer mutation A highly sensitive and selective electrochemical DNA biosensor to diagnose breast cancer A sensitive and selective label-free electrochemical DNA biosensor for the detection of specific dengue virus serotype 3 sequences Electrochemical Label-free and Reagentless Genosensor Based on an Ion Barrier Switch-off System for DNA Sequence-Specific Detection of the Avian Influenza Virus Aptamer based voltammetric biosensor for the detection of Mycobacterium tuberculosis antigen MPT64 Detection of chikungunya virus DNA using two-dimensional MoS2 nanosheets based biosensor A novel electrochemical DNA biosensor for Ebola virus detection Label-free electrochemical biosensor for the detection of Influenza genes and the solution of guanine-based displaying problem of DNA hybridization Novel electrochemical genosensor for Zika virus based on a poly-(3-amino-4-hydroxybenzoic acid)-modified pencil carbon graphite electrode Electrospun manganese (III) oxide nanofiber based electrochemical DNAnanobiosensor for zeptomolar detection of dengue consensus primer DNA-based bioassay of legionella pneumonia pathogen using gold nanostructure: A new platform for diagnosis of legionellosis A sandwich-hybridization assay for simultaneous determination of HIV and tuberculosis DNA targets based on signal amplification by quantum dots-PowerVision TM polymer coding nanotracers An electrochemical immunosensor for the corona virus associated with the Middle East respiratory syndrome using an array of gold nanoparticle-modified carbon electrodes Label-free electrochemical DNA biosensor for zika virus identification A nanocoaxial-based electrochemical sensor for the detection of cholera toxin eCovSens-Ultrasensitive Novel In-House Built Printed Circuit Board Based Electrochemical Device for Rapid Detection of nCovid-19 Labelfree electrochemical detection of prostate-specific antigen based on nucleic acid aptamer Electrochemical impedance spectroscopy of composite adhesive joints A label-free electrochemical impedance cytosensor based on specific peptide-fused phage selected from landscape phage library Label-free impedance biosensors: Opportunities and challenges Interface design for CMOS-integrated Electrochemical Impedance Spectroscopy (EIS) biosensors Ultrasensitive DNA sensor based on gold nanoparticles/reduced graphene oxide/glassy carbon electrode Sex determination based on amelogenin DNA by modified electrode with gold nanoparticle Improved micro-impedance spectroscopy to determine cell barrier properties A review on impedimetric immunosensors for pathogen and biomarker detection Comparison of impedimetric detection of DNA hybridization on the various biosensors based on modified glassy carbon electrodes with PANHS and nanomaterials of RGO and MWCNTs A novel electrochemical DNA biosensor based on a modified magnetic bar carbon paste electrode with Fe3O4NPs-reduced graphene oxide/PANHS nanocomposite Electro-oxidized Monolayer CVD Graphene Film Transducer for Ultrasensitive Impedimetric DNA Biosensor Biotin self-assembled monolayer for impedimetric genosensor for direct detection of HIV-1 Biosensors and Bioelectronics A sensitive impedimetric DNA biosensor for the determination of the HIV gene based on graphene-Na fi on composite film International Journal of Biological Macromolecules Hemagglutinin gene based biosensor for early detection of swine fl u ( H1N1 ) infection in human Biosensors and Bioelectronics Label-free electrochemical DNA biosensor for zika virus identi fi cation Immunosensor Based on Antibody-Nanoparticle Hybrid for Specific Detection of the Dengue Virus NS1 Biomarker OPEN A sensitive electrochemical immunosensor for label-free detection of Zika-virus protein Biosensors in health care: The milestones achieved in their development towards lab-on-chip-analysis Bioelectrochemical Detection of Mycobacterium tuberculosis ESAT-6 in an Antibody-Based Biomicrosystem Ultrasensitive and label-free biosensor for the detection of Plasmodium falciparum histidine-rich protein II in saliva A rapid-response ultrasensitive biosensor for influenza virus detection using antibody modified boron-doped diamond Electrical pulse-induced electrochemical biosensor for hepatitis E virus detection New Trends in Impedimetric Biosensors for the Detection of Foodborne Pathogenic Bacteria Introduction to biosensors Glucose sensors: A review of current and emerging technology Conducting polymer-based electrochemical biosensors for neurotransmitters: A review Guide to Selecting a Biorecognition Element for Biosensors Application of Novel Nanomaterials for Chemo-and Biosensing of Algal Toxins in Shellfish and Water Ion exchange | Ion chromatography instrumentation Enzyme biosensors for biomedical applications: Strategies for safeguarding analytical performances in biological fluids Basics of DNA biosensors and cancer diagnosis B/C genotyping of hepatitis B virus based on dual-probe electrochemical biosensor Sensitive detection of HIV gene by coupling exonuclease III-assisted target recycling and guanine nanowire J o u r n a l P r e -p r o o f amplification A needle-like Cu2CdSnS4 alloy nanostructure-based integrated electrochemical biosensor for detecting the DNA of Dengue serotype 2 Electrochemical DNA biosensor based on a tetrahedral nanostructure probe for the detection of avian influenza A (H7N9) virus Highly specific and rapid glycan based amperometric detection of influenza viruses Glycan and lectin biosensors Mycobacterium tuberculosis Talanta Trends in DNA biosensors Chemical sensors for environmental pollutant determination Microbial biosensors: A review Recent developments in potentiometric biosensors for biomedical analysis Potentiometric biosensor for studying hydroquinone cytotoxicity in vitro Detection principles of biological and chemical FET sensors Development of an aptamer-based field effect transistor biosensor for quantitative detection of Plasmodium falciparum glutamate dehydrogenase in serum samples Biologically sensitive field-effect transistors: From ISFETs to NanoFETs Ion-sensitive field-effect transistor for biological sensing Rapid Detection of COVID-19 Causative Virus (SARS-CoV-2) in Human Nasopharyngeal Swab Specimens Using Field-Effect Transistor-Based Biosensor Glycan-immobilized dualchannel field effect transistor biosensor for the rapid identification of pandemic influenza viral particles Predicting Future Prospects of Aptamers in Field-Effect Transistor Biosensors The authors declare that there is no conflict of interests regarding the publication of this paper. The authors state that they have no established conflicting financial interests or personal relationships, which may seem to have affected the research stated in this article. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.J o u r n a l P r e -p r o o f