Single-step detection of norovirus tuning localized surface plasmon resonance-induced optical signal between gold nanoparticles and quantum dots

Abstract

A new method of label free sensing approach with superior selectivity and sensitivity towards virlabel-freeon is presented here, employing the localized surface plasmon resonance (LSPR) behavior of gold nanoparticles (AuNPs) and fluorescent CdSeTeS quantum dots (QDs). Inorganic quaternary alloyed CdSeTeS QDs were capped with -cysteine via a ligand exchange reaction. Alternatively, citrate stabilized AuNPs were functionalized with 11-mercaptoundecanoic acid to generate carboxylic group on the gold surface. The carboxylic group on the AuNPs was subjected to bind covalently with the amine group of-cysteine capped CdSeTeS QDs to form CdSeTeS QDs/AuNPs nanocomposites. The fluorescence of CdSeTeS QDs/AuNPs nanocomposite shows quenched spectrum of CdSeTeS QDs at 640 nm due to the close interaction with AuNPs. However, after successive addition of norovirus-like particles (NoV-LPs), steric hindrance-induced LSPR signal from the adjacent AuNPs triggered the fluorescence enhancement of QDs in proportion to the concentration of the target NoV-LPs. A linear range of 10 to 10 g mL NoV-LPs with a detection limit of 12.1 × 10 g mL was obtained. This method was further applied on clinically isolated norovirus detection, in the range of 10-10 copies mL with a detection limit of 95.0 copies mL, which is 100-fold higher than commercial ELISA kit. The superiority of the proposed sensor over other conventional sensors is found in its ultrasensitive detectability at low virus concentration even in clinically isolated samples. This proposed detection method can pave an avenue for the development of high performance and robust sensing probes for detection of virus in biomedical applications.

Recent Progress in Optical Sensors for Biomedical Diagnostics

“…The sensitivity of virus detection has been reported to improve by seven orders of magnitude when AuNP (diameter = 26.5 ± 0.5 nm)-quantum dot (QD) nanoconjugates [147] are preferred over AgNPs (diameter = 20-80 nm) [148] as plasmonic nanomaterials owing to the oxidative degradation of AgNPs. Although signal enhancement of AuNPs for virus detection is lower in the case of nanohybrids using CdSeTeS QDs (size = 10.1 ± 2.9 nm) [137,149] or CdZnSeS QDs (size = 4.8 ± 0.6 nm) [147], a 33-fold lower LOD was reported when CdSeS QDs (size = 2.7-7.8 nm) were functionalised with a molecular beacon to obtain hairpin hybridisation assays [146]. Li's group established the superiority of LSPR over electrochemical sensing in the study of several neurotransmitters [117].…”

“…LSPR sensors can be constructed using various types of receptors such as aptamers [55,132,133], antibodies [119,[134][135][136][137][138][139][140], MIPs [141][142][143][144], and nucleic acids [100,145,146]. The combination of LSPR with optical fibres to fabricate ultrasensitive sensors for cancer biomarker diagnosis has transformed into an evolving trend.…”

Label-Free Biosensors for Laboratory-Based Diagnostics of Infections: Current Achievements and New Trends

“…The widespread use of label-free biosensor was facilitated to a large extent by the fact that they use biological or chemical receptors for direct detection of the analyzed molecules in the sample, without the use of special enzyme and radioactive or fluorescent labels. They allow screening of intermolecular interactions and cellular reactions, providing detailed information about the selectivity of effect of bacterial exotoxins and the specificity of antimicrobial agents, the antigen-antibody interaction, as well as the kinetics of inflammatory process, immunological, and serological reactions [3,40,75,76].…”

“…The variety of detection methods and optical converters used in biosensors without labels of this type is huge; therefore, in this review, the authors limited themselves to developments that have successfully established themselves in the detection of biological agents [56,75,76].…”

Immunosensor Based on Long-Period Fiber Gratings for Detection of Viruses Causing Gastroenteritis

“…This sandwich assay enabled the detection of 0.01 ng/mL of norovirus VLPs, but it required multiple incubation and washing steps. A very sensitive method (limit of detection = 95 virus copies/mL) involving regeneration of quenched fluorescence of quantum dots/gold nanoparticles upon addition of the virus was also shown in [17]. However, the selectivity of this assay was limited, with high interferences from other virus particles.…”