Abstract
The safety of cooking oil is a major global concern and capsaicin (CAP) serves as a crucial marker for assessing its quality. To address this issue, we have devised an innovative biosensor using a truncated aptamer, Cap-1–2, as the foundation for a dual-mode aptasensor. The aptasensor employs a combination of Mg2+-dependent DNAzyme (MNAzyme) cleavage and hybridization chain reaction (HCR) to achieve highly sensitive CAP detection. Notably, the fluorescence signal originates from the inherent fluorescence of thioflavin T (ThT) embedded in a G-quadruplex (G4) structure, enabling the detection of CAP in high-throughput oil samples. Additionally, the biosensor employed the MNAzyme to cleave biotinylated DNA (S1-Biotin), which is subsequently ligated to functionalized gold nanoparticles (AuNPs-Poly A-cDNA), generating outstanding colorimetric signals on lateral flow test strips for immediate point-of-care testing (POCT). The linear detection ranges of the established fluorescence and colorimetric aptasensor were 0.15–80 ng mL−1 and 0.2–100 ng mL−1, respectively, and the limits of detection (LOD) were 0.054 ng mL−1 and 0.137 ng mL−1, respectively. These results demonstrate the practicality of the aptasensor for detecting CAP in real-world samples. Moreover, the aptasensor surpasses traditional biosensors in terms of high-throughput, portability, and sensitivity, making it highly promising for rapid detection in the food industry.
Original language | English |
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Article number | 137003 |
Journal | Sensors and Actuators, B: Chemical |
Volume | 425 |
DOIs | |
Publication status | Published - 15 Feb 2025 |
Keywords
- Capsaicin
- Cooking oil
- Food safety
- High-throughput
- Point-of-care testing
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Instrumentation
- Condensed Matter Physics
- Surfaces, Coatings and Films
- Metals and Alloys
- Electrical and Electronic Engineering
- Materials Chemistry