Nanoparticle integrated guar gum hydrogel-based immunosensor for biomedical application

This paper contains results of studies related to fabrication of nanostructured metal oxide (MO) doped guar gum hydrogel (GGH) based immunosensing platform for detection of oral cancer biomarker (CYFRA-21–1). First, we synthesized nanostructured zirconia (nZrO 2 ) through hydrothermal process and thereafter it has been functionalized with serine amino acid. The GGH has been synthesized through chemical process. Further, the solution of nZrO 2 was mixed with GGH in 1:1 ratio in ddH 2 O. The prepared mixture has been further deposited onto a pre-hydrolyzed indium oxide (ITO) coated glass electrode through drop cast method. The anti-CYFRA-21–1 has been immobilized through EDC-NHS chemistry and Bovine Serum Albumin (BSA) has been used for blocking of nonspecific binding sites. X-Ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR) have been used to investigate morphological as well as functional characterization of synthesized material. However, electrochemical studies have been used to characterize fabricated electrodes as well as response studies. The fabricated immunoelectrode (BSA/anti-CYFRA-21–1/Serine/nZrO 2 /Hydrogel/ITO) exhibits a wider linear detection range (2.5–80 ng mL −1 ), remarkably high sensitivity (0.86 µA mg −1 mL cm −2 ) with shelf life up to 48 days. The electrochemical response studies of fabricated electrode have been further validated through enzyme-linked immunosorbent assay (ELISA) on to obtained saliva sample of oral cancer patients. Oral cancer biomarker detection is key for early diagnosis, personalized treatment, monitoring, enabling timely interventions and improved patient outcomes. We can easily investigate the stage of oral cancer through the detection of concentration of biomarkers secreted in saliva sample of oral cancer patients. • Electrochemical immunosensor is developed for oral cancer biomarker detection. • The prepared electrochemical immunosensor is characterized by several methods. • The excellent reliability for protocol of immunosensor fabrication is presented. • This assay is advantageous in comparison with the other analytical methods.