Dual-strain detection of norovirus GI.1 and GII.4 in food samples using epitope-imprinted polymers

Background: Norovirus is the leading cause of viral gastroenteritis worldwide, contributing to widespread disease and financial burdens. However, current testing methods are unsuitable for on-site analysis, as they typically use biological receptors, require specialized reagents, and skilled technicians. Proactive on-site testing of high-risk food samples is essential to prevent outbreaks, requiring the development of innovative sensor systems. Results: We have developed a thermal sensor capable of selectively detecting two recurrent norovirus genotypes, GI.1 and GII.4, within a model food matrix. The sensor uses epitope-imprinted polymer nanoparticles (nanoMIPs) designed from a 10-amino-acid sequence derived from the conserved P1 region of the GI.1 viral capsid. The nanoMIPs demonstrated favorable detection capability to norovirus GI.1 and GII.4 virus-like particles in buffer solutions, achieving detection limits of 1.53 and 2.28 pg/mL, respectively. The selectivity of the nanoMIPs was evaluated against a panel of similar viruses, including murine norovirus, Tulane virus, and bacteriophage MS2, each of which showed a reduced signal. Notably, the sensor achieved rapid detection (30 min) of norovirus GI.1 and GII.4 virus-like particles in contamination prone spinach samples while maintaining comparable detection limits (2.19 pg/mL and 2.69 pg/mL) to spiked buffer solutions. Significance: The combination of rapid detection time, dual strain recognition, and simple sample preparation makes this thermal sensor a promising tool for on-site testing in food safety and public health settings. Furthermore, the ability to detect multiple strains using a single ligand represents a significant advantage, enabling the development of straightforward systems capable of detecting various strains in complex environments.