On chip electrochemical detection of sarcoma protein kinase and HIV-1 reverse transcriptase

In this study, we report a new multiplexed microchip platform exploiting a peptide-modified gold surface and a labeled electrochemical approach. The significance of the presented methodology lies in its ability to test related analytes, such as protein kinases and human immunodeficiency virus (HIV) proteins, that operate under separate mechanisms using a single device without interference. The technology is based on an electrochemical dual sensing mode that can be tuned towards monitoring separately two biochemical events, a biochemical reaction and a direct analyte-receptor binding. The first recognition process is illustrated by a sarcoma-related (Src) protein kinase which catalyzes phosphorylation transfer of a ferrocenoyl-phosphoryl group, from the ferrocene-labeled adenosine triphosphate (Fc-ATP) co-substrate, to the surface-bound target peptide and induces a current response. On the other hand, HIV-1 reverse transcriptase (RT) protein binding to the surface-immobilized ferrocene-labeled target peptide is characterized by a modulation in the current intensity and peak potential. This proof-of-principle study is based on two different biosensing components and serves as a new platform for monitoring multiple analytes of interest. This allowed detection limits of 0.1 μg mL−1 and 50 pg mL−1 for Src kinase and HIV-1 RT, respectively. The miniaturization of the electrochemical protein assay will have an impact in disease detection and treatment.