A unique water soluble probe for measuring the cardiac marker homocysteine and its clinical validation

Abstract

A series of copper(II) compounds 1–4 were synthesized and developed as fluorogenic probes to measure the cardiac marker homocysteine (Hcy) without any interference from other bioanalytes prevalent in human blood plasma including, cysteine and glutathione. UV-vis and EPR studies have provided confirmatory evidence for reduction-induced-emission-enhancement of the probe, which is responsible for the observed “off-to-on” behaviour towards Hcy. Water solubility, remarkable fluorescence enhancement (55–111 fold), and low detection ability (nearly 2.5 μM) make the probe suitable for clinical testing of cardiac samples. Investigation of 1 against a few reductive interferents testifies its specificity for Hcy. Results from clinical examination of cardiac samples by 1 when combined with the outcome of the reliability testing involving a clinically approved commercial immunoassay kit, validates the prospect of the molecular probe for direct measurement of Hcy in human plasma, which is unprecedented.