A Novel Surface Plasmon Resonance Biosensor for the Rapid Detection of Botulinum Neurotoxins.

Kruti Patel,Paul Melman,John Schwartz,Shuowei Cai,Shmuel Halevi,Bal Singh

doi:10.3390/bios7030032

Abstract

Botulinum neurotoxins (BoNTs) are Category A agents on the NIAID (National Institute of Allergy and Infectious Diseases) priority pathogen list owing to their extreme toxicity and the relative ease of production. These deadly toxins, in minute quantities (estimated human i.v. lethal dose LD50 of 1–2 ng/kg body weight), cause fatal flaccid paralysis by blocking neurotransmitter release. The current gold standard detection method, the mouse-bioassay, often takes days to confirm botulism. Furthermore, there are no effective antidotes known to reverse the symptoms of botulism, and as a result, patients with severe botulism often require meticulous care during the prolonged paralytic illness. To combat potential bio-terrorism incidents of botulinum neurotoxins, their rapid detection is paramount. Surface plasmon resonance (SPR) is a very sensitive technique to examine bio-molecular interactions. The label-free, real-time analysis, with high sensitivity and low sample consumption makes this technology particularly suitable for detection of the toxin. In this study, we demonstrated the feasibility in an assay with a newly designed SPR instrument for the rapid detection of botulinum neurotoxins. The LOD (limit of detection) of the Newton Photonics (NP) SPR based assay is 6.76 pg/mL for Botulinum Neurotoxin type A Light Chain (BoNT/A LC). We established that the detection sensitivity of the system is comparable to the traditional mouse LD50 bioassay in BoNT/A using this SPR technology.

Highlights

Botulinum poisoning is a serious and well-recognized biothreat
Newton Photonics (NP) Surface plasmon resonance (SPR) measures the change of refractive index in the TM-polarized beam to a reference beam TE
We developed a novel low-cost waveguide SPR sensor for rapid detection of botulinum neurotoxin

Summary

Introduction

Botulinum poisoning is a serious and well-recognized biothreat. The LC is the proteolytic domain of the BoNT that cleaves one of the soluble N-ethylmaleimide-sensitive factor activating protein receptor (SNARE). Target proteins at the presynaptic termini, leading to inhibition of the neurotransmitter release. The. HC plays an accessary role in binding to nerve cells and the translocation of the LC into the cytosol of nerve cells. HC plays an accessary role in binding to nerve cells and the translocation of the LC into the cytosol of nerve cells Due to their high potency and lack of countermeasures, BoNTs are classified as Category A biothreat agents, and are placed under Tier 1 Select Agents by the US Centers for Disease Control [2,3]

Objectives

Results

Conclusion