Potentiostats for Protein Biosensing: Design Considerations and Analysis on Measurement Characteristics

Abstract

The demand for the development of swift, simple, and ultrasensitive biosensors has been increasing after the introduction of innovative approaches such as bioelectronics, nanotechnology, and electrochemistry. The possibility to correlate changes in electrical parameters with the concentration of protein biomarkers in biological samples is appealing to improve sensitivity, reliability, and repeatability of the biochemical assays currently available for protein investigation. Potentiostats are the required instruments to ensure the proper cell conditioning and signal processing in accurate electrochemical biosensing applications. In this light, this review is aimed at analyzing design considerations, electrical specifications, and measurement characteristics of potentiostats, specifically customized for protein detection. This review demonstrates how a proper potentiostat for protein quantification should be able to supply voltages in a range between few mV to few V, with high resolution in terms of readable current (in the order of 100 pA). To ensure a reliable quantification of clinically relevant protein concentrations (>1 ng/mL), the accuracy of the measurement (<1%) is significant and it can be ensured with proper digital-to-analog (10-16 bits) and analog-to-digital (10-24 bits) converters. Furthermore, the miniaturisation of electrochemical systems represents a key step toward portable, real-time, and fast point-of-care applications. This review is meant to serve as a guide for the design of customized potentiostats capable of a more proper and enhanced conditioning of electrochemical biosensors for protein detection.

A compact, low-cost, and binary sensing (BiSense) platform for noise-free and self-validated impedimetric detection of COVID-19 infected patients

“…Among all electrochemical sensing techniques, the EIS method has gained enormous popularity ( Abdullah et al, 2019 ; Magar et al, 2021 ; Srivastava et al, 2018 ), owing to its high sensitivity in detecting a very low concentration of analytes and its flexibility in utilizing the Faradaic mode of detection for observing the variation in charge transfer resistance (R ct ). The custom-made BiSense bipotentiostat developed in this study is designed for reading the EIS signals from two WEs simultaneously.…”

“…Several researchers have attempted to develop new multichannel potentiostats, but they are neither low-cost enough to be used for low-cost POCT (e.g., for detection of COVID-19 outside of a laboratory) nor sensitive and noise-free enough to meet the high sensitivity needs of ultrasensitive electrochemical biosensors ( Alam et al, 2021 ; Park et al, 2022 ; Ramfos et al, 2013 ; Vinoth et al, 2021 ; Wu et al, 2018 ). The output signals of these readers whether square wave, cyclic voltammetry, or impedance ( Pellitero et al, 2021 ), deals with curve-shaped data that needs further data analysis and curve-fitting approaches to obtain the biosensor data, adding to the complexity of the reader ( Abdullah et al, 2019 ; Bianchi et al, 2019 ; Hoilett et al, 2020 ; Pruna et al, 2018 ; Wu et al, 2018 ). Our multiplex μDrop reader with the capability of simultaneous detection of 1–8 proteins and with comparable performance to the commercial readers was promising toward realizing ME-POCT of panel biomarkers ( Khetani et al, 2021 ).…”

A 77.8-dB DR, 114.2 fJ/Step Amplifier-Less Current-to-Digital Converter

“…Fig. 7 presents the measurement setup for the amperometric technique that measures current by changing the potential applied to the counter electrode (CE) [13]. A control signal is assigned through OP to the CE which is an off-chip control amplifier and takes negative feedback from the reference electrode (RE) to control output; the working electrode (WE) is applied to the on-chip CDC.…”

Emerging Methods in Biosensing of Immunoglobin G—A Review

“…Potentiostatic biosensors are the type of electrochemical biosensor in which the potentiostat detects the voltage difference between the working electrode (WE) and reference electrode (RE) by adjusting the potential difference of the counter electrode with respect to the WE while the resultant potential difference is determined by the concentration of an analyte [ 60 , 61 , 62 ]. These sensors are an important type known as redox-potential biosensors because the redox reaction is the main principle governing these sensors.…”