Microvalve-controlled miniaturized electrochemical lab-on-a-chip based biosensor for the detection of β-amyloid biomarker

Recently, miniaturized electrochemical biosensors have the advantage of real-time monitoring and label-free detection of biomarkers. However, controlled manipulation of reagent samples for specific immobilization of biomarkers remains a challenge to attend high-resolution microfluidic biosensor. Here, we designed a microfluidic channel and valves integrated electrochemical biosensor for the detection of β-amyloid (1–42) biomarker, one of the most neurotoxic peptides present in the cerebrospinal fluid, and a possible marker for the detection of Alzheimer's disease. The formation of the antibody-antigen complexes on gold microelectrode integrated inside the fluidic chambers was presented in the developed biosensor, and all the measurements are carefully controlled using pneumatic valves integrated with the device. The demonstrated microfluidic electrochemical biosensor exhibits a linear response towards various β-amyloid antigen concentrations from 2.2 pM to 22 μM, with an enhanced detection limit of 1.62 pM. The developed technology offers an advantage of minimal reagent sample and suitable environment for miniaturized and sensitive detection of biomarkers, could also be used for the detection of other biomarkers with high efficiency.