The selected antibody was centrifuged in a desalting column to clean and purify it properly and was consequently diluted to 40μg/mL for the modification using a prepared solution of 5mL of FPB containing 50mg of sodium cyanoborohydride. The microneedle array was dipped in 160μL of the antibody solution and placed at 4°C overnight on the SiNPs device.