Enhanced detection of cardiac troponin-I using CdSe/CdS/ZnS core-shell quantum dot/TiO2 heterostructure photoelectrochemical sensor

• Published in: Journal of alloys and compounds 2024-12, Vol.1008, p.176592, Article 176592
• Main Authors: Memon, Roomia, Shaheen, Irum, Qureshi, Anjum, Niazi, Javed H.
• Format: Article
• Language: English
• Subjects: CdSe/CdS/ZnS quantum dots; Charge separation and Photocurrent cardiac biomarker; CTnI; Photoelectrochemical sensor
• ISSN: 0925-8388
• DOI: 10.1016/j.jallcom.2024.176592

This paper introduces a photoelectrochemical sensor employing red-emitting CdSe/CdS/ZnS core-shell quantum dot/TiO2 heterostructure for detecting cardiac troponin-I (cTnI) biomarkers. The sensor utilizes a photoactive layer-by-layer self-assembly of CdSe/CdS/ZnS nanocrystals within a TiO2 nanoparticle photon-sensitive layer to enhance charge separation, thereby boosting sensor photocurrent. Additionally, the CdSe/CdS/ZnS quantum dot layer enhances photocurrent stability by facilitating the separation of photo-excited electrons and holes. Functionalization of the CdSe/CdS/ZnS core-shell quantum dot/TiO2 heterostructure-based photoelectrochemical sensor with anti-troponin involves first activating -COOH functionalized CdSe/CdS/ZnS with carbodiimide cross-linkers, followed by cTnI protein capture. Photocurrent changes are measured using amperometry. The sensor format exhibits an enhanced photocurrent signal proportional to concentration, with a detection range of 10 pg/mL to 0.2 ng/mL of cTnI protein. The use of a red-emitting CdSe/CdS/ZnS quantum dot layer ensures chemical stability during and after chemical coupling on the sensor. This study showcases the successful application of CdSe/CdS/ZnS core-shell quantum dot/TiO2 heterostructure-based photoelectrochemical sensors for early detection of troponin-I protein in cardiac disease diagnostics. •Innovative sensor design employing CdSe/CdS/ZnS quantum dots for troponin-I detection.•Enhanced detection sensitivity spanning from 10 pg/mL to 0.2 ng/mL.•Improved photocurrent stability facilitated by the quantum dot layer.•Practical application potential for early diagnosis of cardiac diseases.