Abstract
With COVID-19 widespread worldwide, people are still struggling to develop faster and more accurate diagnostic methods. Here we demonstrated the label-free detection of SARS-CoV-2 spike protein by employing a SARS-CoV-2 spike antibody-conjugated phase-shifted long-period fiber grating (PS-LPFG) inscribed with a CO 2 laser. At a specific cladding mode, the wavelength separation (λ D ) between the two split dips of a PS-LPFG varies with the external refractive index, although it is virtually insensitive to ambient temperature variations. To detect SARS-CoV-2 spike protein, SARS-CoV-2 spike antibodies were immobilized on the fiber surface of the fabricated PS-LPFG functionalized through chemical modification. When exposed to SARS-CoV-2 spike protein with different concentrations, the antibody-immobilized PS-LPFG exhibited the variation of λ D according to the protein concentration, which was caused by bioaffinity binding-induced local changes in the refractive index at its surface. In particular, we also confirmed the potential of our sensor for clinical application by detecting SARS-CoV-2 spike protein in virus transport medium. Moreover, our sensor could distinguish SARS-CoV-2 spike protein from those of MERS-CoV and offer efficient properties such as reusability and storage stability. Hence, we have successfully fabricated a promising optical transducer for the detection of SARS-CoV-2 spike protein, which can be unperturbed by external temperature disturbances.
Keywords: COVID-19; Coronavirus; Long-period fiber grating; Phase shift; SARS-CoV-2; Surface functionalization.
【저자키워드】 COVID-19, SARS-CoV-2, coronavirus, Long-period fiber grating, Phase shift, surface functionalization, 【초록키워드】 antibody, Variation, Local, MERS-CoV, Spike protein, stability, SARS-CoV-2 spike protein, temperature, optical, variations, surface, diagnostic methods, SARS-CoV-2 spike, Phase shift, phase, transport medium, ambient temperature, refractive index, Modification, offer, protein concentration, virus transport medium, ambient, fiber, widespread, concentrations, detect, develop, caused, exhibited, changes in, faster, demonstrated, 【제목키워드】 fiber,