Visible-light-driven rhodamine 6G mediated in situ poly-ferrocene strategy for highly sensitive quantification of esophageal cancer biomarkers.

Esophageal cancer (EC) is one of the most prevalent malignant tumors globally, and the core strategy to improve the survival prospects of EC patients is to identify high-risk lesions and subsequently administer efficacious treatments. Among numerous biomarkers, microRNAs have the potential to facilitate rapid cancer screening and prevention. Therefore, a highly sensitive detection method based on photoinduced electron transfer atom transfer radical polymerization (PET-ATRP) signal amplification strategy was designed, aiming to accurately detect the potential markers of EC. The biosensor employs an indium tin oxide (ITO) electrode as a carrier, immobilizes probe 1 on the electrode surface by silanization, and achieves effective capture of tRNA with a stable sandwich structure to introduce -SH group. Subsequently, an ATRP initiator was introduced to the electrode surface by forming disulfide bonds, which resulted in the growth of poly-ferrocene under the catalysis of rhodamine 6G (R6G) and blue light irradiation. The R6G-mediated PET-ATRP signal amplification strategy offers significant advantages of simplicity, rapidity and cost-effectiveness while enhancing the sensitivity of the biosensor to tRNA with a limit of detection of 0.12 fM. Moreover, the biosensor exhibits excellent selectivity and anti-interference ability in real samples, which has significant potential for the timely prevention and diagnosis of EC.