Reduced graphene oxide modified screen-printed electrode with bioengineered surface for voltammetric detection of prostate-specific antigen in oncological urine samples.

In this work, reduced graphene oxide modified screen-printed electrode modified with anti-prostate specific antigen (anti-PSA linked using N-ethyl-N'-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide) was developed for early electrochemical detection of PSA. Constructed sensing interface gave linear dynamic range from 0.10 fg mL-1 to 100.00 ng mL-1 with a calculated limit of detection 0.10 fg mL-1, low limit of quantification 1.04 fg mL-1 and high sensitivity 10.02 μA mL·ng-1. PSA detection was done in artificial urine and commercial serum, respectively, in the RSD range of 4.02-4.57 and 1.72 to 2.0. Moreover, a developed nanoimmunochip was applied to successfully detect the PSA in two oncological urine samples, further verified by ELISA. Finally, a nanoimmunochip stored at -20 °C for 60 days demonstrated comparable performance to a freshly developed platform.