Detection of VEGF165 in Whole Blood by Differential Pulse Voltammetry Based on a Centrifugal Microfluidic Chip

For the rapid and sensitive detection of vascular endothelial growth factor 165 (VEGF165) in clinical blood samples, amicrofluidic sensing chip that integrates a centrifugal separationpretreatment unit and a composite nanosensingfilm was proposed inthis paper. An efficient sensing strategy and method was established. Theblood sample wasfirst separated and extracted by centrifugal force on thecentrifugal microfluidic chip within 5 min after injection. The separatedplasma can be automatically transferred through the designed micro-channels to the detection area integrated electrodes for subsequentdifferential pulse voltammetric detection. The Au NPs/MCH/Apt2sensingfilm was constructed on the surface of the Au working electrode.A sandwich sensing strategy based on"double aptamers"and"nanop-robe"for VEGF165detection was established, by which the synthetic Apt1/PThi/Au NP nanoprobe was applied to capture VEGF165in plasma and bind to the sensingfilm. By this method, the detection limit of VEGF165in whole blood was 0.67 pg/mL and the linearrange was between 1 pg and 10 ng, which met the needs of clinical VEGF165detection. It was illustrated that the proposedmethodology based on the centrifugal microfluidic chip had potential application prospects in the development of the point-of-care testing fields