Development of a Compact System Integrating Pre-Concentrator and Electrochemical Measurements for Protein Pre-Concentration and Detection

This study presents the research and development of an embedded system integrating a pre-concentrator and an electrochemical measurement circuit for the concentration and detection of proteins in a microfluidic chip. The system is composed of five main blocks, namely the central control unit, measurement circuit, voltage controller, bio-chip, and graphical user interface (GUI). After the design, the system was fabricated using the multilayer layer printed circuit board (PCB) and monolithic aluminum processing techniques. Additionally, embedded software was developed for the microcontroller, and a graphical user interface (GUI) was created for screen interaction, facilitating the execution of system functions. The experimental results demonstrate that the proposed system is capable of generating output voltages ranging from 15 V to 90 V with a response time of 300 ms. The pre-concentrator functioned effectively in both depletion and enrichment modes using bovine serum albumin–fluorescein isothiocyanate conjugate (BSA-FITC). Notably, in the enrichment mode, the fluorescence intensity of the concentration zone increased from 28 A.U to 55 A.U after seven minutes. Moreover, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements were conducted using standard redox solution and Randles equivalent circuit, respectively. The measurement results closely resembled those obtained from commercial devices, affirming the system's performance and reliability. In the future, a point-of-care testing system can be developed for protein quantification and cancer diagnosis.