title: The mechanism of an enzymatic reaction-induced SERS transformation for the study of enzyme-molecule interfacial interactions.
abstract: We report the observation of a novel effect in which the vibrational frequencies and spectral intensity of enzyme (E)-conjugated surface-enhanced Raman scattering (SERS)-active reporter molecules (4-mercaptobenzoic acid (4-MBA)) shift and change regularly as a function of the concentration of the substrate molecule (S). We attribute the frequency shifts and intensity changes in the E-reporter complex to the binding of S to the active site of E, which affects the electronic structure, polarizability and electron density of the molecule. Our observations demonstrate the creation of an E-conjugated SERS-active reporter complex as a SERS-active nano-mechanical sensor for bio-detection. Specifically, we used glucose oxidase (GOx), which was capable of achieving detection sensitivity comparable to that of a conventional sandwich enzymatic reaction. Furthermore, 2D correlation SERS spectroscopy was performed to better investigate the glucose-responsive mechanism, and the results of these experiments support our proposed conclusion. These findings pave a new pathway for utilizing the specific response to glucose via the SERS method, which can achieve a detection limit of 10-6mol L-1for glucose and cover a much wider concentration range, including the blood glucose concentrations in healthy (3-8 mmol L-1) and diabetic (9-40 mmol L-1) individuals, than the current chromogenic assays.
authors.affiliation: State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun, 130012, P. R. China and Department of Chemistry, Institute for Molecular Science and Fusion Technology, Kangwon National University, Chunchon 24341, Korea. ymjung@kangwon.ac.kr.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Yu
authors.affiliation: Key Laboratory of Preparation and Applications of Environmental Friendly Materials, Ministry of Education, Jilin Normal University, Siping 136000, P. R. China.
authors.forename: Lei
authors.identifier: http://orcid.org/0000-0003-2616-2190
authors.initials: L
authors.lastname: Chen
authors.affiliation: Department of Chemistry, Institute for Molecular Science and Fusion Technology, Kangwon National University, Chunchon 24341, Korea. ymjung@kangwon.ac.kr.
authors.forename: Yeonju
authors.initials: Y
authors.lastname: Park
authors.affiliation: Key Laboratory for Bionic Engineering of Ministry of Education, Jilin University, Changchun 130025, P. R. China. congqian@jlu.edu.cn.
authors.forename: Qian
authors.initials: Q
authors.lastname: Cong
authors.affiliation: State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun, 130012, P. R. China.
authors.forename: Xiaoxia
authors.initials: X
authors.lastname: Han
authors.affiliation: State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun, 130012, P. R. China.
authors.forename: Bing
authors.initials: B
authors.lastname: Zhao
authors.affiliation: Department of Chemistry, Institute for Molecular Science and Fusion Technology, Kangwon National University, Chunchon 24341, Korea. ymjung@kangwon.ac.kr.
authors.forename: Young Mee
authors.initials: YM
authors.lastname: Jung
mesh_terms: D001565:Benzoates / Q000737:chemistry; D015374:Biosensing Techniques / Q000379:methods; D001786:Blood Glucose / Q000032:analysis; D020134:Catalytic Domain; D005942:Gluconates / Q000737:chemistry; D005947:Glucose / Q000737:chemistry*; D005949:Glucose Oxidase / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry; D008956:Models, Chemical; D011485:Protein Binding; D012834:Silver / Q000737:chemistry; D013059:Spectrum Analysis, Raman; D013438:Sulfhydryl Compounds / Q000737:chemistry
chemical_list: D001565:Benzoates; D001786:Blood Glucose; D005942:Gluconates; D013438:Sulfhydryl Compounds; C013594:4-mercaptobenzoate; D012834:Silver; D005949:Glucose Oxidase; D005947:Glucose; C030691:gluconic acid