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.
Subject(s)
Antibodies/isolation & purification , Biosensing Techniques , Electrodes , Immunoglobulin A/isolation & purification , Animals , Antibodies/chemistry , Electrochemical Techniques , Potassium Chloride/chemistryABSTRACT
This paper experimentally investigates the effectiveness of electronic dispersion compensation (EDC) for signals limited by self phase modulation (SPM) and various dispersion levels. The sources considered are low-cost conventional directly modulated lasers (DMLs), fabricated for operation at 2.5 Gb/s but modulated at 10 Gb/s. Performance improvement is achieved by means of electronic feed-forward and decision-feedback equalization (FFE/DFE) at the receiver end. Experimental studies consider both transient and adiabatic chirp dominated DMLs sources. The improvement is evaluated in terms of required optical signal-to-noise ratio (ROSNR) for bit-error-rate (BER) values of 10(-3) versus launch power over uncompensated links of standard single mode fiber (SSMF).
