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 wellcontrolled 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.

Applications of gold nanoparticles in medicine and therapy

“…Tang et al developed a simple and reproducible SERS chip for highly sensitive and selective screening of active ricin in complex matrices. 69 They fabricated single strand oligodeoxynucleotides modified AuNPs in order to amplify recognition and reaction by virtue of their cooperative binding property. To improve sensitivity of this method, a Ag nanoshell was deposited on post-reacted poly (21dA)-AuNPs, which lowered LOD to 8.9 ng mL…”

Advanced AuNMs as nanomedicine’s central goals capable of active targeting in both imaging and therapy in biomolecules

“…Compared to conventional detecting methods such as those based on PCR, the method was demonstrated to be rapid, facile and very sensitive. Tang et al developed a simple and reproducible SERS chip for highly sensitive and selective screening of active ricin in complex matrices [63]. They fabricated single strand oligodeoxynucleotides modified AuNPs in order to amplify recognition and reaction by virtue of their cooperative binding property.…”

Facile On‐Site Detection Based on Reactional Wettability Variation

“…However, some indicator preparations or detection operations are usually too complicated in designing and to perform. Receiving of some signals requires devices sometimes . In particular, most fluorescent probes need to be excited by extra operations when in use.…”