Simultaneous detection of microcysin-LR and okadaic acid using a dual fluorescence resonance energy transfer aptasensor

• Published in: Analytical and bioanalytical chemistry Vol. 407; no. 5; pp. 1303 - 1312
• Main Authors: Wu, Shijia, Duan, Nuo, Zhang, Hui, Wang, Zhouping
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.02.2015; Springer; Springer Nature B.V
• Subjects: Acids; Algae; Analytical Chemistry; Aptamers, Nucleotide - chemistry; Bioassays; Biochemistry; Biosensing Techniques - instrumentation; Biosensing Techniques - methods; Biosensors; Characterization and Evaluation of Materials; Chemical properties; Chemistry; Chemistry and Materials Science; Chromatography; Contamination; Decapoda; Deoxyribonucleic acid; Energy transfer; Fluorescence; Fluorescence Resonance Energy Transfer - instrumentation; Fluorescence Resonance Energy Transfer - methods; Food contamination & poisoning; Food Contamination - analysis; Food Science; Foods; Fourier transforms; Identification and classification; Immunoassay; Isomerism; Laboratory Medicine; Lasers; Luminescence; Luminescence quenching; Microcystins - chemistry; Monitoring/Environmental Analysis; Nanomaterials; Nanoparticles; Nitrates; Okadaic Acid - analysis; Research Paper; Seafood - analysis; Toxins; Upconversion; Beijing China; United States > US; China; Japan; Microcysin-LR; Okadaic acid; Aptamer; Simultaneous detection; Upconversion nanoparticles
• ISSN: 1618-2642; 1618-2650
• DOI: 10.1007/s00216-014-8378-3

Algal toxins can cause neurovirulence, hepatotoxicity, and cytotoxicity in humans through the consumption of contaminated water and food. In this work, we presented a novel aptasensor for the simultaneous detection of two algal toxins, microcysin-LR (MC-LR) and okadaic acid (OA). This system employed green and red upconversion nanoparticle (UCNP) luminescence as the donors and two quenchers (BHQ 1 and BHQ 3 ) as the corresponding acceptors. The two donor–acceptor couples were fabricated by hybridizing the aptamers with their corresponding complementary DNA. The results indicated that the green and red upconversion luminescence could be quenched by the quencher probes because of their highly overlapping spectrum. In the presence of MC-LR and OA, the aptamers preferred to bind to their corresponding analytes and de-hybridize with the complementary DNA. This effect became sufficiently large to prevent green and red luminescence quenching. Under the optimized experimental conditions, the relative luminescence intensity increased as the algal toxin concentrations increased, allowing for the quantification of MC-LR and OA. The relationships between the luminescence intensity and plotting logarithms of algal toxin concentrations were linear in the range from 0.1 to 50 ng mL −1 for MC-LR and OA. As a practical application, this type of dual fluorescence resonance energy transfer (FRET) aptasensor was used to monitor the MC-LR and OA levels in naturally contaminated food samples such as fish and shrimps. Graphical Abstract Schematic illustration of dual FRET aptasensor between the upconversion nanoparticles and quenching agent for the simultaneous detection of MC-LR and OA