Luminescence “Turn-On”\nSensing of Brain\nNatriuretic Peptide (BNP) - Dilated Cardiomyopathy Biomarker Based\non the MoS<sub>2</sub> Nanosheet Quenched Terbium Citrate Complex

Dilated cardiomyopathy (DCM), known as myocardial metabolic\ndysfunction,\nis recognized as a clinical condition characterized by left ventricular\ndilation or improper contraction of cardiac muscles in the absence\nof coronary atherosclerosis and hypertension. It is an independent\nrisk factor for cardiac function caused by a hyperglycemic condition\nin diabetic patients leading to heart failure (HF), which renders\nthe early diagnosis of DCM highly challenging. Hence, detection of\nearly diagnostic biomarkers in blood serum to identify DCM conditions\nis quite requisite. Brain natriuretic peptide (BNP) is a well-recognized\nbiomarker for heart failure and reported as an early diagnostic biomarker\nfor DCM. In this work, we developed a terbium citrate based MoS<sub>2</sub> nanosheet (NS) coupled immunoprobe for the sensitive detection\nof BNP. The antibody conjugated Tb-citrate complex exhibits green\nfluorescence, which is quenched by the introduction of MoS<sub>2</sub> NS. On subsequent addition of antigen BNP, the fluorescence is enhanced\nbecause of specific antigen–antibody interaction. The probe\nis selective and sensitive toward BNP in a linear range from 30.76\nto 849.85 pg/mL with a low LOD of 3.87 pg/mL. The probe is validated\nin spiked human serum samples with good recovery percentage.