A Ti 3 C 2 T X /Pt-Pd based amperometric biosensor for sensitive cancer biomarker detection.

The detection of cancer biomarkers is of great significance for the early screening of cancer. Detecting the content of sarcosine in blood or urine has been considered to provide a basis for the diagnosis of prostate cancer. However, it still lacks simple, high-precision and wide-ranging sarcosine detection methods. In this work, a Ti 3 C 2 T X /Pt-Pd nanocomposite with high stability and excellent electrochemical performance has been synthesized by a facile one-step alcohol reduction and then used on a glassy carbon electrode (GCE) with sarcosine oxidase (SO x ) to form a sarcosine biosensor (GCE/Ti 3 C 2 T X /Pt-Pd/SO x ). The prominent electrocatalytic activity and biocompatibility of Ti 3 C 2 T X /Pt-Pd enable the SO x to be highly active and sensitive to sarcosine. Under the optimized conditions, the prepared biosensor has a wide linear detection range to sarcosine from 1 to 1000 µM with a low limit of detection of 0.16 µM (S/N = 3) and a sensitivity of 84.1 µA/mM cm 2 . Besides, the reliable response in serum samples shows its potential in the early diagnosis of prostate cancer. More importantly, the successful construction and application of the amperometric biosensor based on Ti 3 C 2 T X /Pt-Pd will provide a meaningful reference for detecting other cancer biomarkers.