title: Structure-selective hot-spot Raman enhancement for direct identification and detection of trace penicilloic acid allergen in penicillin.
abstract: Trace penicilloic acid allergen frequently leads to various fatal immune responses to many patients, but it is still a challenge to directly discriminate and detect its residue in penicillin by a chemosensing way. Here, we report that silver-coated gold nanoparticles (Au@Ag NPs) exhibit a structure-selective hot-spot Raman enhancement capability for direct identification and detection of trace penicilloic acid in penicillin. It has been demonstrated that penicilloic acid can very easily link Au@Ag NPs together by its two carboxyl groups, locating itself spontaneously at the interparticle of Au@Ag NPs to form strong Raman hot-spot. At the critical concentration inducing the nanoparticle aggregation, Raman-enhanced effect of penicilloic acid is ~60,000 folds higher than that of penicillin. In particular, the selective Raman enhancement to the two carboxyl groups makes the peak of carboxyl group at C6 of penicilloic acid appear as a new Raman signal due to the opening of β-lactam ring of penicillin. The surface-enhanced Raman scattering (SERS) nanoparticle sensor reaches a sensitive limit lower than the prescribed 1.0‰ penicilloic acid residue in penicillin. The novel strategy to examine allergen is more rapid, convenient and inexpensive than the conventional separation-based assay methods.
authors.affiliation: School of Pharmacy, Nanjing Medical University, Nanjing, Jiangsu 211166, China.
authors.forename: Liying
authors.initials: L
authors.lastname: Zhang
authors.affiliation: School of Pharmacy, Nanjing Medical University, Nanjing, Jiangsu 211166, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Jin
authors.affiliation: School of Pharmacy, Nanjing Medical University, Nanjing, Jiangsu 211166, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Mao
authors.affiliation: School of Pharmacy, Nanjing Medical University, Nanjing, Jiangsu 211166, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zheng
authors.affiliation: School of Pharmacy, Nanjing Medical University, Nanjing, Jiangsu 211166, China.
authors.forename: Jiawei
authors.initials: J
authors.lastname: Zhao
authors.affiliation: School of Pharmacy, Nanjing Medical University, Nanjing, Jiangsu 211166, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Peng
authors.affiliation: School of Pharmacy, Nanjing Medical University, Nanjing, Jiangsu 211166, China. Electronic address: shuhudu@njmu.edu.cn.
authors.forename: Shuhu
authors.initials: S
authors.lastname: Du
authors.affiliation: Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei, Anhui 230031, China. Electronic address: zpzhang@iim.ac.cn.
authors.forename: Zhongping
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D000485:Allergens / Q000032:analysis*; D004340:Drug Contamination / Q000517:prevention & control; D004353:Drug Evaluation, Preclinical / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008832:Microchemistry / Q000295:instrumentation; D010397:Penicillanic Acid / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry; D010406:Penicillins / Q000032:analysis / Q000737:chemistry*; D011358:Product Surveillance, Postmarketing / Q000379:methods; D013059:Spectrum Analysis, Raman / Q000295:instrumentation*
chemical_list: D000485:Allergens; D010406:Penicillins; C008782:penicilloic acid; D006046:Gold; D010397:Penicillanic Acid
keywords: Core–shell nanoparticles; Hot-spot; Penicillin; Penicilloic acid; SERS; Sensor