Quantum-Dot-Based Molecularly Imprinted Hydrogel for Rapid Detection of Homocysteine

Elevated levels of homocysteine (Hcy) are associated with various pathological conditions including atherosclerosis, hypertension, and cardiovascular diseases. In this work, quantum-dot-based molecularly imprinted hydrogels (QD@MIHs) were developed by integrating L-cysteine-modified ZnS quantum dots (QDs)with highly selective molecular imprinting technology for rapid homocysteine detection. The QD@MIPHs were fabricated using a dual-functional monomer system (acrylamide and methacrylic acid) through surface coating of the Hcy molecularly imprinted polymer gel onto the QDs. Under optimal conditions, the response time of the QD@MIPHs for Hcy detection was 5 min. When the Hcy concentration ranged from 0.1 to 10.0 μM, the fluorescence quenching of the QD@MIHs showed a good linear relationship with Hcy concentration (R² = 0.9972), with a corresponding detection limit of 0.027 μM. In addition, the constructed QD@MIPHs showed no significant response to other interfering substances, demonstrating the high selectivity of the prepared material. Practical sample analysis revealed that the recovery rates of Hcy ranged from 94.34% to 104.1%, with relative standard deviations (RSD, n = 3) between 3.56% and 7.17%. This study provides a novel tool and method for rapid Hcy detection with significant potential in biomedical diagnostics and preventive-healthcare applications.