MXenes-Based Fiber-Optic SPR Sensor for Colorectal Cancer Diagnosis

A highly sensitive spectral surface plasmon resonance (SPR) based fiber-optic sensor is proposed to diagnose the colorectal cancer that develops in the colon or rectal of intestine. Proposed sensor consists of transition metal carbides known as MXenes having chemical formula Ti(3)C(2)Tx based layered materials. The high sensitivity of fiber-optic sensor is attributed to high intercalation capacity, large surface area of 93.6 m(2) g(-1), hydrophilic nature, biocompatibility, good thermal stability and high electrical conductivity of two-dimensional (2D) MXenes. The performance of sensor is analyzed under wavelength interrogation method in the wavelength range of 400 nm to 1000 nm. The dependence of angular characteristics of a multimode fiber-based sensor is investigated theoretically by optimizing the resonance curves to obtain the maximum sensitivity (S) and Figure of merit (FOM). The potential of two most popular plasmonic metals gold (Au) and silver (Ag) is demonstrated to compare the performance of the sensor. The sensor design is able to differentiate between normal and cancerous colorectal state due to their different refractive indices (RIs). The maximum sensitivity and FOM obtained in case of Au-Ti3C2 based sensing probe is 6854.3 nm/RIU and 45.69 RIU-1. The sensitivities of Ag, Ag-Ti3C2F2, Ag-Ti3C2(OH)(2), Ag-Ti3C2O2, Ag-Ti3C2 based sensor are 6230.70 nm/RIU, 6308.46 nm/RIU, 6620.12 nm/RIU, 6386.31 nm/RIU and 10766.28 nm/RIU, respectively. The presence of MXenes in Ag based sensor enhances the sensitivity and FOM nearly 2 times compared to Au based sensor. Ultrahigh sensitivity of 10766.28 nm/RIU and FOM of 76.90 RIU-1 with low detection limit with Ag-Ti3C2 based sensor is highest among the earlier reported fiber-optic SPR sensor for colorectal cancer detection.

Automated summary

A highly sensitive spectral surface plasmon resonance (SPR) based fiber-optic sensor is proposed for the diagnosis of colorectal cancer. The sensor utilizes MXene materials with high intercalation capacity, large surface area, hydrophilic nature, biocompatibility, thermal stability, and electrical conductivity. By optimizing the resonance curves, the sensor achieves maximum sensitivity and figure of merit, and can differentiate between normal and cancerous colorectal states.