Human serum albumin directed formation of cadmium telluride quantum dots: Applications in biosensing, anti-bacterial activities and cell cytotoxicity measurements

• Published in: International journal of biological macromolecules Vol. 268; no. Pt 1; p. 131862
• Main Authors: Haque, Mahabul, Kalita, Mitul, Chamlagai, Dipak, Lyndem, Sona, Koley, Sudipta, Kumari, Puja, Aguan, Kripamoy, Singha Roy, Atanu
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.05.2024
• Subjects: Anti-bacterial; Biosensing; CdTe-HSA QDs; Cell cytotoxicity; Fluorescence; Quenching; Fluorescence; Anti-bacterial; CdTe-HSA QDs; Cell cytotoxicity; Biosensing; Quenching
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2024.131862

Although cadmium-based quantum dots (QDs) are highly promising candidates for numerous biological applications, their intrinsic toxicity limits their pertinency in living systems. Surface functionalization of QDs with appropriate molecules could reduce the toxicity level. Herein, we have synthesized the smaller sized (1–5 nm) aqueous-compatible biogenic CdTe QDs using human serum albumin (HSA) as a surface passivating agent via a greener approach. HSA-functionalized CdTe QDs have been explored in multiple in vitro sensing and biological applications, namely, (1) sensing, (2) anti-bacterial and (3) anti-cancer properties. Using CdTe-HSA QDs as a fluorescence probe, a simple fluorometric method has been developed for highly sensitive and selective detection of blood marker bilirubin and hazardous Hg2+ ion with a limit of detection (LOD) of 3.38 and 0.53 ng/mL, respectively. CdTe-HSA QDs also acts as a sensor for standard antibiotics, tetracycline and rifampicin with LOD values of 41.34 and 114.99 ng/mL, respectively. Nano-sized biogenic CdTe-HSA QDs have shown promising anti-bacterial activities against both gram-negative, E. coli and gram-positive, E. faecalis strains confirming more effectiveness against E. faecalis strains. The treatment of human cervical cancer cell lines (HeLa cells) with the synthesized QDs reflected the proficient cytotoxic properties of QDs. Herein, we have reported the HSA-directed synthesis of CdTe QDs and explored the multiple biological applications, namely (1) biosensing applications, (2) anti-bacterial activity, and (3) cell cytotoxicity against HeLa cancer cell line. [Display omitted] •HSA directed synthesis of CdTe quantum dots (QDs) have been synthesized using a greener approach.•Nano-dimensional (1–5 nm) CdTe-HSA QDs are highly aqueous compatible and stable.•Synthesized CdTe-HSA QDs are excellent sensing probe for Hg2+ ion as revealed from steady-state fluorescence measurements.•Selective detections of biomarker bilirubin and antibiotics were also conducted using CdTe-HSA QDs.•CdTe-HSA QDs have shown potential anti-bacterial and cell cytotoxicity effects under in vitro conditions.