Ratiometric Fluorescence Capillary Sensor-Integrated Molecular Imprinting for Simultaneous Detection of Two Biological Indicators of Parkinson’s Disease

This work proposed ratiometric fluorescence capillary sensing system-integrated molecular imprinting with highly sensitive and selective detection for two biological indicators of Parkinson's disease (homovanillic acid (HVA) and Al³⁺). In this research, the silicon carbon quantum dot and the near-infrared CdTe quantum dot as luminescence sources were doped to an imprinted layer, which was attached to the inner surface wall of an amino-functionalized capillary. The fluorescence emissions of the ratiometric fluorescence capillary-imprinted sensor at 434 and 707 nm were quenched by HVA, and only the fluorescence emission at 434 nm was quenched by Al³⁺. Ratiometric fluorescence capillary sensing system-integrated molecular imprinting was used to detect simultaneously HVA and Al³⁺ with linearity over 1.0 × 10^-9-2.5 × 10^-7 and 1.0 × 10^-9-1.1 × 10^-7 M, respectively. The sensor showcased detection limitations of 8.7 × 10^-10 and 9.8 × 10^-10 M, indicating that the ratiometric fluorescence capillary sensing system-integrated molecular imprinting had great potential application for detecting HVA and Al³⁺ in serum and urine samples. The ratiometric fluorescence capillary sensing system-integrated molecular imprinting achieved highly sensitive and selective detection of HVA and Al³⁺ with a microvolume test dosage of 18 μL, which provided a new way for early diagnosis and disease monitoring of Parkinson's disease.