Fluorescent Quantum Dots Based Lateral Flow Assay for Rapid Quantitative Detection of Ciliary Neurotrophic Factor in Glaucoma

Early and accurate diagnosis of glaucoma is crucial to prevent the progressive deterioration that leads to irreversible vision loss. It is imperative to develop an effective screening tool for glaucoma. Ciliary neurotrophic factor (CNTF) is a tear biomarker implicated in glaucoma pathogenesis. Lateral flow assay (LFA) provides an ideal platform for detection of glaucoma in tear fluid. A quantum dot-based fluorescence LFA, integrated with a 3D printed readout box, is developed for fast (30 min), sensitive, and quantitative CNTF detection in tears. A standard curve is firstly generated for the quantitative detection of CNTF. The limit of detection (LOD) of the obtained LFA strip at 6.45 pg·mL⁻¹ is comparable to that of the enzyme-linked immunosorbent assay (ELISA) at 6.42 pg·mL⁻¹. This enables the identification of low CNTF levels (25.7 ± 14.9 pg·mL⁻¹) reported in tear fluid from glaucoma patients. This LFA is found to be highly selective for CNTF and maintained consistent results in different pH condition. The strip remaines stablewhen stored in the darkat room temperature. A smartphone app is developed to simplify analysis and enable prompt and easily obtainable results. This method shows great potential to be a powerful tool for point-of-care glaucoma screening.