title: Proximity hybridization-regulated chemiluminescence resonance energy transfer for homogeneous immunoassay.
abstract: Chemiluminescence resonance energy transfer (CRET) and the proximity ligation assay have been widely used in design of sensors for the bioanalysis. Here, a wash-free and homogeneous strategy was proposed to detect carcino-embryonic antigen (CEA) based on proximity hybridization-regulated CRET. The Cy5 demonstrated strong chemiluminescence (CL) via the oxidation of TCPO in the presence of H2O2 and energy transfer between excited TCPO and Cy5. Graphene oxide (GO) as an excellent quencher was used to produce the "Signal off" mode that little CL emission was observed through CRET between GO and the Cy5-labelled DNA3. Once CEA was introduced, the target-induced proximity hybridization occurred to form a proximate complex, which inhibited the CRET by preventing GO from absorbing Cy5-labelled DNA3. Furthermore, taking advantage of nicking endonuclease Nt.BbvCI for in situ recycling, the signal could be further amplified for highly sensitive CL detection. Our results showed that this strategy enabled a specific response to CEA with a detection range of 5 orders of magnitude, along with a detection limit of 3.2pg mL(-1). Apart from its easy operation, high sensitivity and acceptable accuracy, the proposed method needed only 0.3μL of sample, indicating its great opportunity for commercial application.
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.
authors.forename: Mengmeng
authors.initials: M
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China. Electronic address: wujie@nju.edu.cn.
authors.forename: Jie
authors.initials: J
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.
authors.forename: Kaili
authors.initials: K
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Zong
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.
authors.forename: Jianping
authors.initials: J
authors.lastname: Lei
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.
authors.forename: Huangxian
authors.initials: H
authors.lastname: Ju
mesh_terms: D004735:Energy Transfer; D006861:Hydrogen Peroxide; D007118:Immunoassay; D049449:Luminescence; D008163:Luminescent Measurements
chemical_list: D006861:Hydrogen Peroxide
keywords: CEA; Chemiluminescence resonance energy transfer; Graphene oxide; Immunoassay; Proximity hybridization