3.2.1. Lectin biosensor:
Lectin-based biosensors determines the measurable signal by estimating the conversion of lectin-carbohydrate interactions. Lectins have a high affinity to multivalent oligosaccharides. Lectins’ extremely specific binding to terminal carbohydrate moieties on cell surfaces and protein aggregates is used in physiological and pathological studies, such as virus and bacterium detection and glycol profiling of serum glycoproteins. Electrochemical lectin-based biosensors can be used to diagnose illness and pathogens by detecting biomarkers (Coelho et al., 2017), as well as biorecognition of glycan in viral proteins (Cesewski & Johnson, 2020).
SARS-COV-2 envelope glycoprotein might be exploited for early detection using lectin-based biosensors. Another use of lectin-based electrochemical biosensors includes the use of cyclic voltammetry and impedance to detect norovirus (nonenveloped virus) in feces samples without showing cross-reactivity with hepatitis A or E (Hong et al., 2015). The impedimetric lectin-based biosensor can also be applied for differentiating chikungunya virus, Zika virus, yellow fever and DENV-2 in serum-based samples (Simao et al., 2020).
Liao et al. (2016) described a lectin-based biosensor made from the marine mollusk Crenomytilus grayanus (CG) that may be used to diagnose and treat cancer. The CGL crystal can attach to three ligands: galactose, galactosamine, and globotriose (Gb3), and it may be utilized to recognize Gb3 on the surface of breast cancer cells, causing them to die. Peiris et al. (2012) developed a lectin-based biosensor using N-acetylgalactosamine lectin from the Roman snail Helix pomatia agglutinin (HPA) (Helix pomatia). This HPA based biosensor can have an affinity for metastatic SW620 cells and non-metastatic SW480 in different molar ranges.
This approach is the latest approach for the selective determination and quantification of cancer-specific glycans and lectin.