Quantum dots have been widely used for biomedical applications like imaging, targeted drug delivery, and in-vitro diagnostics for better sensitivity. In-vitro diagnostic, lateral flow-based assay systems are gaining attention in the field of biomarker analysis mainly due to ease of test and quick availability of results. In the study, the potential of water-soluble carboxylic (-COOH) functionalized photoluminescent Cadmium Telluride Quantum Dots (CdTe) nanoparticles for lateral flow-based detection of N-terminal Natriuretic Peptide (NT-proBNP) biomarker (for heart failure) detection has been evaluated. Monoclonal antibodies were conjugated with COOH functionalized CdTe with EDC-NHS coupling chemistry, and conjugation was confirmed using FTIR. The CdTe nanoparticle exhibited an emission maximum at 715 nm when it is excited with 375 nm. The COOH functionalized CdTe showed an antigen concentration-dependent linearity in the lateral flow applications when the dye was prepared freshly and used. However, a relative reduction in CdTe quantum dot fluorescence intensity with time was observed. Factors such as low stability could be due to the quenching of the fluorescence of CdTe. This limits its commercial viability as an in-vitro diagnostic tool; thus, modifications of the quantum dots are required to have a stable preparation for its commercial potential for quantifications.
Keywords: Diagnostics; NT-proBNP; fluorescence; quantum dots.