A microfluidics chemiluminescence immunosensor based on orientation of antibody for HIV-1 p24 antigen detection

The HIV-1 capsid protein, p24 antigen, is a recognizable early diagnostic biomarker for human immune deficiency virus (HIV) infection. However, the existing methods address the limitations of high cost, cumbersome operations, long analysis time, and insufficient sensitivity and selectivity. Herein, an antibody oriented microfluidic chemiluminescence biosensor based on multiple signal amplification strategy was developed for rapid and ultrasensitive detection of HIV-1 p24 antigen. The microfluidic device contained an upstream snake-shape mixing channel and a downstream ship-shape microcavity with micropillar arrays for sufficient mixing of CL reagents, efficient capture of p24 antigen, double antibody sandwich reaction, hybridization chain reaction (HCR) amplification and CL detection. The multiple signal amplification was realized by antibody orientation, multiple HCRs on antibody and initiator chain modified gold nanoparticles (Ab2-AuNPs-I), and HRP and AuNPs synergistic catalyzed CL reaction. Using the platform, the detection of target p24 is converted to the detection of nucleic acid with a limit detection of 0.212 pg mL−1 and excellent specificity within 2 h of total analysis time, which is better or comparable to previously reported biosensors. Moreover, the biosensor exhibited an excellent recovery rate ranging from 92.7% to 102.3%. Therefore, the proposed method holds great potential in clinical diagnosis.