Background noise interferes with the accurate detection of early tumor biomarkers. This study introduces a method that effectively reduces background noise to enhance detection accuracy by combining a color-coded signaling approach with the unique fluorescent properties and room-temperature tunable quantum spin characteristics of fluorescent diamonds (FNDs) with nitrogen-vacancy centers. In this approach, a red signal indicates the presence of the target analyte within the spectral region, a green signal indicates its absence, and a yellow signal indicates the need for further analysis using FNDs' quantum spin properties for optical detection magnetic resonance (ODMR) to distinguish the FND signal from background noise. Preliminary results demonstrate that this method enables the detection of breast cancer-related miRNA-21 and miRNA-96 concentrations as low as 1 fM within a 100 × 100 μm2 area, achieving single-molecule detection capability. This method is suitable for accurate biomarker identification and detection under high-background fluorescence conditions.
Keywords: Accurate detection; color-coded; miRNAs; nitrogen-vacancy centers; quantum sensing; traffic signal method.