Optimization of ACEK-enhanced, PCB-based biosensor for highly sensitive and rapid detection of bisphenol a in low resource settings

In this study, we developed a low-cost and easy-to-use capacitive biosensor employing printed-circuit-board (PCB)-based technique for electrode fabrication and a specific alternative current (AC) signal for AC Electrokinetics (ACEK) effect excitation. Fast, accurate, and highly sensitive detection and quantification of bisphenol A (BPA) was achieved. An easy characterization of the biofunctionalization process is introduced by measuring interfacial capacitance which is simple and superior to most of methods currently in use. The frequency and amplitude of the AC signal used for capacitive interrogation were optimized to achieve maximum interfacial capacitance and maximum sensitivity. To evaluate the performance of the developed biosensor, its operation was compared with in-house microfabricated and commercially available electrodes. The limit-of-detection (LOD) obtained using the PCB-based electrodes was found to be at least one order of magnitude lower than that obtained with the commercial and in-house microfabricated electrodes. The linear range for BPA detection was wide from 1 fM to 10 pM with an LOD of 109.5 aM and sample to result in 20s. The biosensor operation was validated by spike-and-recovery tests of BPA using commercial food samples. Thus, the platform has a potential as an on-site detection of bisphenol A in low-resource settings.