| Description |
Colorectal cancer (CRC) is the third most common cancer worldwide. By 2030, it is expected that approximately 2.2 million new cases of CRC will be diagnosed globally, half of which will be fatal due to belated screenings. Many of the issues preventing early and accurate CRC diagnoses are related to limitations of the current diagnostic technologies. Colonoscopy, being the current gold-standard detection method, has its fair share of challenges: prohibitive costs, extreme invasiveness, extensive preparation, and postprocedure complications. Recent discoveries of some volatile organic compounds (VOCs), in the breaths of CRC patients, have opened up new vistas for developing an inexpensive, noninvasive and rapid diagnostic tool for early detection of CRC. The objective of the present studies was to fabricate and improve a nickel-functionalized titanium dioxide nanotube array (Ni-TNA) sensor that will be able to detect four critical breath-based biomarkers (cyclohexane, 1,3 dimethylbenzene, methylcyclohexane, and decanal) found in CRC patients. A standard anodization process was used to synthesize the TNA on to which nickel was electrodeposited in the form of Ni(OH)2 nanoparticles. Detection of the VOCs, both in solution and vapor samples, was carried out by cyclic voltammetry (CV). For gas-phase CVs, a planar electrode setup with the graphene-embedded polylactic acid (G-PLA) conducting polymeric electrolyte was used. Normal and VOC-spiked breath samples from a healthy subject were also tested with the fabricated sensor. CV measurements provided distinct electrochemical signatures for each of the four iv biomarkers in acidic solution. Gaseous VOCs could individually be detected in the presence of an inert, acidified polar solvent that may have increased conductivity. Pronounced CV features in the spiked-VOC breath samples were also observed. These results demonstrate the sensor's sensitivity to its environment and its applicability in both solution and gaseous/vapor phase detections. G-PLA performed quite well as an electrolyte and facilitated recording of the CVs in gas-phase, something that has never been done before. The research results obtained in these studies have demonstrated the potential future opportunities for the development of a portable, noninvasive, inexpensive, and versatile electrochemical-based sensor for the detection of critical organic compounds found in CRC and other cancer patients. |
