Early Detection of Cancer using Calreticulin as a Protein Biomarker in Waveguide‐Mode Resonant Gratings Structure

Abstract

This paper presents a simulated design of a label-free guided mode resonance–based biosensor for the early diagnosis of cancer. A nano-pattern periodic film of biomarker is induced on a waveguide mode to produce a waveguide-mode resonant gratings effect. With the incorporation of resonant waveguide grating (RWG) technology, the sensor exhibits sharp resonance peaks at 61.8 nm in E polarization and 60 nm in H polarization under normal incidence. As the angle of incidence increases beyond the resonance peak splits into double resonance and widens accordingly. The detection and quantification of the biomarkers in the grating layer of the proposed biosensor decides the up-regulation or down-regulation of the biomarkers in the blood/serum of the patient. The proposed sensor design can sense the binding events in the range of 3nm to 5nm scale thickness marking the sensitivity in picomolar (pM) range. The proposed label-free biosensor exhibits a low surface-localized effective refractive index(RI) sensitivity of approximately 3 nm/RIU over the RI range of 1.48–1.52, offering marginal signal stability and enabling reliable real-time detection with minimal sample processing. The proposed simulated biosensor detects cancer-causing alterations by sensing variations in chaperone concentration, with 68 nM taken as the standard prognostic reference.