基于SERS阵列的铜绿假单胞菌代谢产物铜绿菌素即时检测

SERS array toward point-of-care detection of Pseudomonas aeruginosa metabolite

铜绿假单胞菌可导致临床慢性感染,是烧伤、泌尿道感染、囊性纤维化等感染的重要致病菌。铜绿菌素是铜绿假单胞菌产生的次生代谢产物,可导致感染患者细胞死亡,与高死亡率息息相关,可作为铜绿假单胞菌检测的生物标志物。铜绿菌素的直接、即时检测能够极大程度降低临床上铜绿假单胞菌的诊断时间,提高临床治疗的效率。为实现以上目标,在本文中,我们通过静电吸附的机理在氨基硅烷化的玻片表面修饰一层AgNPs,构建了一种简单、价格低廉的具有表面增强拉曼效应的阵列传感平台,以实现培养基及唾液中铜绿菌素的直接、快速检测。结果表明铜绿菌素主要的SERS峰位主要为420,543,597,680,1354,1598和1615 cm^(-1),其中用来进行定量分析的420 cm^(-1)和1615 cm^(-1)处拉曼位移分别归属于-CCN环弯曲和-C-N弯曲,及C=C环拉伸和C=N环拉伸。通过对肉汤培养基和唾液中的铜绿菌素直接检测,发现检测限分别为0.5 M和0.35 M,远低于临床样本中铜绿菌素的检测浓度,每个样品的检测时间为10 s。这表明我们所构建的SERS基底阵列,具备适用于临床上铜绿假单胞菌代谢产物铜绿菌素的高灵敏即时检测的潜力。

Pseudomonas aeruginosa which can lead to chronic clinical infection is an important pathogen of burns,urinary tract infection and cystic fibrosis.As the secondary metabolites produced by P.aeruginosa,pyocyanin(PYO)can cause cell death in patients with infection,closely related to high mortality.Therefore,the direct and rapid detection of PYO,as the biomarker of P.aeruginosa,is able to reduce the analysis time and improve the diagnostic effect.Here,we constructed a SERS array platform using silver nanoparticles modified glass slides via electrostatic adsorption to achieve the direct and rapid detection of pyocyanin in the culture medium and saliva.The results showed that,the main SERS peak shifts of PYO were mainly 420,543,597,680,1354,1598 and 1615 cm^(-1).The Raman shifts at 420 cm^(-1) and 1615 cm^(-1) used for quantitative analysis were respectively attributed to-CCN ring bending and C=N ring bending,as well as C=C ring stretching and C=N ring stretching.The limit of detection of PYO in broth medium and saliva were 0.5 M,and 0.35 M,respectively.It is far below the detection concentration of PYO in clinical samples.This shows that the surface modified SERS array we constructed has the potential to be capable of the point-of-care detection clinically with high sensitivity of the metabolites of P.aeruginosa.