Trace Determination of Grouper Nervous Necrosis Virus in Contaminated Larvae and Pond Water Samples Using Label-Free Fiber Optic Nanoplasmonic Biosensor

Abstract

We developed a fast (<20 min), label-free fiber optic particle plasmon resonance (FOPPR) immunosensing method to detect nervous necrosis virus (NNV), which often infects high-value economic aquatic species, such as grouper. Using spiked NNV particles in a phosphate buffer as samples, the standard calibration curve obtained was linear (R2 = 0.99) and the limit of detection (LOD) achieved was 2.75 × 104 TCID50/mL, which is superior to that obtained using enzyme-linked immunosorbent assay (ELISA). By using an enhancement method called fiber optic nanogold-linked immunosorbent assay (FONLISA), the LOD can be further improved to <1 TCID50/mL, which is comparable to that found by the conventional qPCR method. Employing the larvae homogenate samples of NNV-infected grouper, the results obtained by the FOPPR biosensor agree with those obtained by the quantitative polymerase chain reaction (qPCR) method. We also examined pond water samples from an infected container in an indoor aquaculture facility. The lowest detectable level of NNV coat protein was found to be 0.17 μg/mL, which is one order lower than the LOD reported by ELISA. Therefore, we demonstrated the potential of the FOPPR biosensor as an outbreak surveillance tool, which is able to give warning indication even when the trend of larvae death toll increment is still not clear.

Competitive Assay for the Ultrasensitive Detection of Organophosphate Pesticides Based on a Fiber-Optic Particle Plasmon Resonance Biosensor and an Acetylcholinesterase Binding Peptide

“…Furthermore, the use of normalized intensity Δ I / I 0 in this method allows some fluctuations of I 0 , and thus, the requirements for high precision in sensor chip fabrication and optical alignment are lessened. Recently, the application of the FOPPR biosensor for in-field operation at a pond site has been demonstrated …”

“…Recently, the application of the FOPPR biosensor for in-field operation at a pond site has been demonstrated. 56 Quantitative Analysis of Parathion in Spiked Water and Vegetable Samples. The feasibility and reliability of the method were also verified by performing the analysis using tap water and cauliflower vegetable samples.…”