title: FRET-based modified graphene quantum dots for direct trypsin quantification in urine.
abstract: A versatile nanoprobe was developed for trypsin quantification with fluorescence resonance energy transfer (FRET). Here, fluorescence graphene quantum dot is utilized as a donor while a well-designed coumarin derivative, CMR2, as an acceptor. Moreover, bovine serum albumin (BSA), as a protein model, is not only served as a linker for the FRET pair, but also a fluorescence enhancer of the quantum dots and CMR2. In the presence of trypsin, the FRET system would be destroyed when the BSA is digested by trypsin. Thus, the emission peak of the donor is regenerated and the ratio of emission peak of donor/emission peak of acceptor increased. By the ratiometric measurement of these two emission peaks, trypsin content could be determined. The detection limit of trypsin was found to be 0.7 μg/mL, which is 0.008-fold of the average trypsin level in acute pancreatitis patient's urine suggesting a high potential for fast and low cost clinical screening.
authors.affiliation: Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region.
authors.forename: Chung-Yan
authors.initials: CY
authors.lastname: Poon
authors.affiliation: Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region.
authors.forename: Qinghua
authors.initials: Q
authors.lastname: Li
authors.affiliation: Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region; Research Center of Environmental Science and Engineering, School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, PR China.
authors.forename: Jiali
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region; Research Center of Environmental Science and Engineering, School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, PR China.
authors.forename: Zhongping
authors.initials: Z
authors.lastname: Li
authors.affiliation: Research Center of Environmental Science and Engineering, School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, PR China.
authors.forename: Chuan
authors.initials: C
authors.lastname: Dong
authors.affiliation: Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region.
authors.forename: Albert Wai-Ming
authors.initials: AW
authors.lastname: Lee
authors.affiliation: Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region.
authors.forename: Wing-Hong
authors.initials: WH
authors.lastname: Chan
authors.affiliation: Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region. Electronic address: hwli@hkbu.edu.hk.
authors.forename: Hung-Wing
authors.initials: HW
authors.lastname: Li
mesh_terms: D015374:Biosensing Techniques; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D057230:Limit of Detection; D046529:Microscopy, Electron, Transmission; D045663:Quantum Dots; D014357:Trypsin / Q000652:urine*
chemical_list: D006108:Graphite; D014357:Trypsin
keywords: BSA; Coumarin; FRET; GQD; Trypsin