Biosensors and Bioelectronics: X (Sep 2022)
A high throughput dual-signal ultra-sensitive electrochemical and photoelectrochemical microfluidic immunoassay platform with raspberry Au/PANI@CdS for Cyfra 21-1 detection
Abstract
The excellent integration capability of microfluidic platform provides infinite possibilities for the development of analysis and detection technology. A microfluidic immunoassay platform was designed by combining the screen printing and microfluidic chip manufacturing. Four screen printed electrodes were applied as detection units and were divided into two groups for the generation of both electrochemical and photoelectrochemical signals. The light source for the photoelectrochemical process was achieved by the integration of two LED lamp beads in the 3D printed chip holder. Check valves between the chambers of working units and auxiliary units were exploited for the separated steps of working electrode modification and signal detection. A sandwich-type immunosensing configuration was adoped using raspberry-like Au/PANI@CdS nanocomposites as signal tags. Electrochemical and photoelectrochemical current signals can be detected simultaneously on a multichannel electrochemical workstation. After the optimization of microfluidic parameters and other experimental conditions, the microfluidic immunoassay platform shows good analytical performances for the detection of Cyfra 21-1 in the range of 0.1 pg/mL ∼100 ng/mL, with the PEC detection limit of 0.035 pg/mL and the DPV detection limit of 0.041 pg/mL. This multi-functional high-throughput portable microfluidic immunoassay platform has great application prospect in disease diagnosis and instant detection.
