Polydimethylsiloxane microfluidic chemiluminescence immunodevice with the signal amplification strategy for sensitive detection of human immunoglobin G

• Signal amplification strategy was used on PDMS microfluidic CL immunodevice.
• The antibody was immobilized inside the double spiral microchannel.
• AuNPs functionalized with a high molar ratio of HRP were used as an Ab label.
• The CL signal of human IgG showed an increase of 7.4-fold in detection sensitivity.

A polydimethylsiloxane (PDMS) microfluidic chemiluminescence (CL) immunodevice for sensitive detection of human immunoglobin G (IgG) with the signal amplification strategy was developed in this work. The immunodevice was prepared by covalently immobilizing capture antibodies (Abs) on the silanized microchannel of microfluidic chip. Gold nanoparticles (AuNPs) functionalized with a high molar ratio of horseradish peroxidase (HRP) were used as an Ab label for signal amplification. Using a sandwich immunoassay, the multi-HRP conjugated AuNPs can catalyze the luminol-H2O2 CL system to achieve the high sensitivity. In addition, the double spiral flow-channel was adopted here, which can still contribute to the high sensitivity. Based on signal amplification strategy, the performance of human IgG tests revealed a lower detection limit (DL) of 0.03 ng/mL and showed an increase of 7.4-fold in detection sensitivity compared to a commercial Ab-HRP conjugation. This microfluidic immunodevice can provide an alternative approach for sensitive detection of human IgG in the field of clinic diagnostic and therapeutic.

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