title: New Surface-Enhanced Raman Sensing Chip Designed for On-Site Detection of Active Ricin in Complex Matrices Based on Specific Depurination.
abstract: Quick and accurate on-site detection of active ricin has very important realistic significance in view of national security and defense. In this paper, optimized single-stranded oligodeoxynucleotides named poly(21dA), which function as a depurination substrate of active ricin, were screened and chemically attached on gold nanoparticles (AuNPs, ∼100 nm) via the Au-S bond [poly(21dA)-AuNPs]. Subsequently, poly(21dA)-AuNPs were assembled on a dihydrogen lipoic-acid-modified Si wafer (SH-Si), thus forming the specific surface-enhanced Raman spectroscopy (SERS) chip [poly(21dA)-AuNPs@SH-Si] for depurination of active ricin. Under optimized conditions, active ricin could specifically hydrolyze multiple adenines from poly(21dA) on the chip. This depurination-induced composition change could be conveniently monitored by measuring the distinct attenuation of the SERS signature corresponding to adenine. To improve sensitivity of this method, a silver nanoshell was deposited on post-reacted poly(21dA)-AuNPs, which lowered the limit of detection to 8.9 ng mL(-1). The utility of this well-controlled SERS chip was successfully demonstrated in food and biological matrices spiked with different concentrations of active ricin, thus showing to be very promising assay for reliable and rapid on-site detection of active ricin.
authors.affiliation: State Key Laboratory of Toxicology and Medical Countermeasures, and Laboratory of Toxicant Analysis, Institute of Pharmacology and Toxicology, Academy of Military Medical Sciences , Beijing 100850, People's Republic of China.
authors.forename: Ji-Jun
authors.initials: JJ
authors.lastname: Tang
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, People's Republic of China.
authors.forename: Jie-Fang
authors.initials: JF
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, People's Republic of China.
authors.forename: Rui
authors.initials: R
authors.lastname: Lui
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, People's Republic of China.
authors.forename: Zong-Mian
authors.initials: ZM
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, People's Republic of China.|Institute of Environment and Health, Jianghan University , Wuhan, Hubei 430056, People's Republic of China.
authors.forename: Jing-Fu
authors.initials: JF
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Toxicology and Medical Countermeasures, and Laboratory of Toxicant Analysis, Institute of Pharmacology and Toxicology, Academy of Military Medical Sciences , Beijing 100850, People's Republic of China.
authors.forename: Jian-Wei
authors.initials: JW
authors.lastname: Xie
mesh_terms: D006046:Gold / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D011687:Purines / Q000737:chemistry*; D012276:Ricin / Q000032:analysis*; D013056:Spectrophotometry, Ultraviolet; D013059:Spectrum Analysis, Raman / Q000379:methods*
chemical_list: D009838:Oligodeoxyribonucleotides; D011687:Purines; D006046:Gold; D012276:Ricin
keywords: active ricin; depurination; gold nanoparticles; on-site detection; surface-enhanced Raman spectroscopy