title: A compact hybrid-multiplexed potentiostat for real-time electrochemical biosensing applications.
abstract: The architecture and design of a compact, multichannel, hybrid-multiplexed potentiostat for performing electrochemical measurements on continuously-biased electrode arrays is presented. The proposed architecture utilises a combination of sequential and parallel measurements, to enable high performance whilst keeping the system low-cost and compact. The accuracy of the signal readout is maintained by following a special multiplexing approach, which ensures the continuous biasing of all the working electrodes of an array. After sampling the results, a digital calibration technique factors out errors from component inaccuracies. A prototype printed circuit board (PCB) was designed and built using off-the-shelf components for the real-time measurement of the amperometric signal of 48 electrodes. The operation and performance of the PCB was evaluated and characterised through a wide range of testing conditions, where it exhibited high linearity (R(2)>0.999) and a resolution of 400pA. The effectiveness of the proposed multiplexing scheme is demonstrated through electrochemical tests using KCl and [Fe(CN)6](3-) in KCl solutions. The applicability of the prototype multichannel potentiostat is also demonstrated using real biosensors, which were applied to the detection of IgA antibodies.
authors.affiliation: Applied Electronics Laboratory, Department of Electrical and Computer Engineering, University of Patras, Rion, Greece. iram@micro2gen.com
authors.forename: Ioannis
authors.initials: I
authors.lastname: Ramfos
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Vassiliadis
authors.forename: Spyridon
authors.initials: S
authors.lastname: Blionas
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Efstathiou
authors.forename: Alex
authors.initials: A
authors.lastname: Fragoso
authors.forename: Ciara K
authors.initials: CK
authors.lastname: O'Sullivan
authors.forename: Alexios
authors.initials: A
authors.lastname: Birbas
mesh_terms: D000818:Animals; D000906:Antibodies / Q000737:chemistry / Q000302:isolation & purification*; D015374:Biosensing Techniques; D055664:Electrochemical Techniques; D004566:Electrodes; D007070:Immunoglobulin A / Q000302:isolation & purification*; D011189:Potassium Chloride / Q000737:chemistry
chemical_list: D000906:Antibodies; D007070:Immunoglobulin A; D011189:Potassium Chloride