Photonic crystals utilized for label-free and amplified fluorescence biodetection

Abstract

Photonic crystals are fabricated on plastic surfaces, producing narrow bandwidth resonances at any desired wavelength. While shifts in the resonant wavelength quantify the density of adsorbed biomaterial, the resonances also enhance the output of adsorbed fluorophores. The combined attributes of photonic crystals enable highly sensitive label-free detection and greatly amplified sensitivity of any fluorescence-based assay for applications in life science research, drug discovery, and environmental pathogen detection. Applications for label-free selective detection of viral pathogens with sensitivity of ~30 focal forming units, and detection of spore pathogens with single-unit resolution are highlighted. Amplified fluorescence, meanwhile, enables gene expression detection of DNA at concentrations ~2 orders of magnitude lower than detection on optically passive surfaces.

Recent Advances in Early Diagnosis of Viruses Associated with Gastroenteritis by Biosensors

“…The leading transmission route of rotavirus is through fecal–oral contact; however, according to considerable shedding of rotavirus in stool during diarrhea, in some developing countries with poor sanitation systems, the virus can transmit via contaminated water. Thus, the detection of rotavirus in water sources is considered to be a preventive tool and is as important as a laboratory diagnosis that detects the virus in infected individuals [ 110 ]. Standard rotavirus detection techniques, except for the enzyme-linked immunoassay (ELISA), are not recommended by the World Health Organization (WHO) due to their laborious and resource-intensive procedure [ 111 ], and this is where various types of biosensors can be used as the potential alternative methods.…”