Sensitive immunosensing of melanoma biomarker based on enhanced electrochemiluminescence via electronic metal-support interactions

Developing highly sensitive and convenient immunosensor for the detection of biomarker is important for enhancing the effectiveness of melanoma prevention and control measures. In this work, immunosensor was fabricated for sensitive detection of the melanoma biomarker S100B based on enhanced electrochemiluminescence (ECL) via electronic metal-support interactions. CoAl-layered double hydroxide (LDH) was selected as to modify the costless indium tin oxide (ITO) electrode due to its high surface area and tunable structure. To improve its conductivity and electron transfer capability, oxygen vacancies (Ov) were introduced on LDH through an alkaline etching process, resulting in the LDH-Ov structure. Platinum nanoparticles (Pt) were then <i>in situ</i> loaded onto the LDH-Ov surface (Pt@LDH-Ov/ITO). The electronic metal-support interaction (EMSI) between LDH-Ov and Pt nanoparticles played a critical role in improving the catalytic activity, leading to an enhanced ECL signal in the luminol-dissolved oxygen (DO) system. The immunorecognition interface was fabricated on Pt@LDH-Ov/ITO, enabling selective detection of S100B. The constructed immunosensor exhibited a linear detection range for S100B from 100 fg/mL to 100 ng/mL, with a limit of detection (LOD) of 65 fg/mL. The high performance and enhanced sensitivity of the immunosensor make it a promising tool for the early diagnosis, monitoring of recurrence, and personalized treatment of melanoma.