title: Facile and ultrasensitive fluorescence sensor platform for tumor invasive biomaker β-glucuronidase detection and inhibitor evaluation with carbon quantum dots based on inner-filter effect.
abstract: Early detection and diagnosis have great practical significances for the effective prevention and treatment of cancer. In this study, we developed a novel, facile and ultra-sensitive fluorescence assay for the determination of tumor invasive biomarker β-glucuronidase (GLU) based on the inner-filter effect (IFE). The nitrogen-doped carbon quantum dots (N-CQDs) with green photoluminescence were employed as the fluorophore in IFE, and 4-nitrophenyl-β-D-glucuronide (PNPG) was used to act as GLU substrate, and GLU catalytic product (p-nitrophenol (PNP)) was capable of acting as the robust absorber in IFE to turn off the fluorescence of N-CQDs due to the complementary overlap between the absorption of PNP and the excitation of N-CQDs. Thus, signal of GLU activity could be recorded by the fluorescence intensity of N-CQDs. Unlike other fluorescence sensing mechanism such as fluorescence resonance energy transfer (FRET) or photoinduced electron transfer (PET), IFE has no requirement for electron or energy transfer process or any chemical modification of fluorophore, which makes our assay more flexible and simple. The proposed method exhibited a good linear relationship from 1UL(-1) to 60UL(-1) (R(2)=0.9967) with a low detection limit of 0.3UL(-1). This method was also successfully applied to the analysis of serum samples and the inhibitor screening from natural product. The developed sensor platform was proven to be reliable, facile, sensitive, and selective, making it promising as a candidate for GLU activity detection in clinic tumor diagnose and anti-tumor drug screening.
authors.affiliation: Key Laboratory of Life-Organic Analysis of Shandong Province, Qufu Normal University, Qufu 273165, People's Republic of China.
authors.forename: Shuaimin
authors.initials: S
authors.lastname: Lu
authors.affiliation: Key Laboratory of Life-Organic Analysis of Shandong Province, Qufu Normal University, Qufu 273165, People's Republic of China; Key Laboratories of Chemical Safety and Health, China National Center for Food Safety Risk Assessment, Beijing 100050, People's Republic of China. Electronic address: 61254368@163.com.
authors.forename: Guoliang
authors.initials: G
authors.lastname: Li
authors.affiliation: Key Laboratory of Life-Organic Analysis of Shandong Province, Qufu Normal University, Qufu 273165, People's Republic of China.
authors.forename: Zhengxian
authors.initials: Z
authors.lastname: Lv
authors.affiliation: Key Laboratories of Chemical Safety and Health, China National Center for Food Safety Risk Assessment, Beijing 100050, People's Republic of China.
authors.forename: Nannan
authors.initials: N
authors.lastname: Qiu
authors.affiliation: Key Laboratory of Life-Organic Analysis of Shandong Province, Qufu Normal University, Qufu 273165, People's Republic of China.
authors.forename: Weiheng
authors.initials: W
authors.lastname: Kong
authors.affiliation: Key Laboratory of Life-Organic Analysis of Shandong Province, Qufu Normal University, Qufu 273165, People's Republic of China.
authors.forename: Peiwei
authors.initials: P
authors.lastname: Gong
authors.affiliation: Key Laboratory of Life-Organic Analysis of Shandong Province, Qufu Normal University, Qufu 273165, People's Republic of China.
authors.forename: Guang
authors.initials: G
authors.lastname: Chen
authors.affiliation: Key Laboratory of Life-Organic Analysis of Shandong Province, Qufu Normal University, Qufu 273165, People's Republic of China.
authors.forename: Lian
authors.initials: L
authors.lastname: Xia
authors.affiliation: Key Laboratory of Life-Organic Analysis of Shandong Province, Qufu Normal University, Qufu 273165, People's Republic of China.
authors.forename: Xiaoxi
authors.initials: X
authors.lastname: Guo
authors.affiliation: Key Laboratory of Life-Organic Analysis of Shandong Province, Qufu Normal University, Qufu 273165, People's Republic of China; Key Laboratory of Tibetan Medicine Research, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810001, People's Republic of China. Electronic address: jmyou6304@163.com.
authors.forename: Jinmao
authors.initials: J
authors.lastname: You
authors.affiliation: Key Laboratories of Chemical Safety and Health, China National Center for Food Safety Risk Assessment, Beijing 100050, People's Republic of China. Electronic address: wuyongning@cfsa.net.cn.
authors.forename: Yongning
authors.initials: Y
authors.lastname: Wu
mesh_terms: D015374:Biosensing Techniques / Q000379:methods; D002244:Carbon / Q000737:chemistry*; D004354:Drug Screening Assays, Antitumor / Q000379:methods; D057075:Enzyme Assays / Q000379:methods; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005456:Fluorescent Dyes / Q000737:chemistry*; D005966:Glucuronidase / Q000032:analysis / Q000037:antagonists & inhibitors* / Q000097:blood*; D006801:Humans; D057230:Limit of Detection; D009584:Nitrogen / Q000737:chemistry; D045663:Quantum Dots / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods*
chemical_list: D004791:Enzyme Inhibitors; D005456:Fluorescent Dyes; D002244:Carbon; D005966:Glucuronidase; D009584:Nitrogen
keywords: Anti-tumor drug screening; Inner-filter effect; Nitrogen-doped carbon quantum dots; β-glucuronidase