Label-Free Fluorescence Assay of S1 Nuclease and Hydroxyl Radicals Based on Water-Soluble Conjugated Polymers and WS₂ Nanosheets.
We developed a new method for detecting S1 nuclease and hydroxyl radicals based on the use of water-soluble conjugated poly[9,9-bis(6,6-(N,N,N-trimethylammonium)-fluorene)-2,7-ylenevinylene-co-alt-2,5-dicyano-1,4-phenylene)] (PFVCN) and tungsten disulfide (WS₂) nanosheets. Cationic PFVCN is used as a signal reporter, and single-layer WS₂ is used as a quencher with a negatively charged surface. The ssDNA forms complexes with PFVCN due to much stronger electrostatic interactions between cationic PFVCN and anionic ssDNA, whereas PFVCN emits yellow fluorescence. When ssDNA is hydrolyzed by S1 nuclease or hydroxyl radicals into small fragments, the interactions between the fragmented DNA and PFVCN become weaker, resulting in PFVCN being adsorbed on the surface of WS₂ and the fluorescence being quenched through fluorescence resonance energy transfer. The new method based on PFVCN and WS₂ can sense S1 nuclease with a low detection limit of 5 × 10(-6) U/mL. Additionally, this method is cost-effective by using affordable WS₂ as an energy acceptor without the need for dye-labeled ssDNA. Furthermore, the method provides a new platform for the nuclease assay and reactive oxygen species, and provides promising applications for drug screening.
Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, China. lijunting@snnu.edu.cn.
Junting
J
Li
Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, China. lunar0315@163.com.
Qi
Q
Zhao
Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, China. yltang@snnu.edu.cn.
Yanli
Y
Tang
D015374:Biosensing Techniques / Q000379:methods*; D004277:DNA, Single-Stranded / Q000737:chemistry; D004720:Endonucleases / Q000737:chemistry / Q000302:isolation & purification*; D005449:Fluorenes / Q000737:chemistry; D031541:Fluorescence Resonance Energy Transfer; D017665:Hydroxyl Radical / Q000737:chemistry / Q000302:isolation & purification*; D057230:Limit of Detection; D049329:Nanostructures / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D017382:Reactive Oxygen Species / Q000737:chemistry; D017973:Tungsten Compounds / Q000737:chemistry; D014867:Water / Q000737:chemistry
D004277:DNA, Single-Stranded; D005449:Fluorenes; D011108:Polymers; D017382:Reactive Oxygen Species; D017973:Tungsten Compounds; D014867:Water; D017665:Hydroxyl Radical; C041509:fluorene; D004720:Endonucleases
S1 nuclease; WS2 nanosheet; conjugated polymers; fluorescent sensing; hydroxyl radicals; label-free