Desenvolvimento de um biossensor para detecção de células tumorais através de lectinas

Abstract

Cancer represents one of the leading causes of mortality worldwide, making early detection fundamental to increase patient survival chances. This work developed electrochemical biosensors based on laser-induced graphene functionalized with BanLec lectin from Musa acuminata to detect tumor cells through recognition of aberrant glycosylation patterns. The objective consisted of developing a LIG-type electrochemical biosensor for tumor cell detection through recognition of abnormal glycosylation patterns using BanLec lectin, contributing to the advancement of non-invasive oncological diagnosis in body fluids. The study produced LIG sensors by direct laser writing on polyimide substrates, followed by covalent functionalization with BanLec lectin through EDC/NHS chemistry. Electrochemical characterization utilized cyclic voltammetry and differential pulse voltammetry. To optimize performance, a hybrid system was developed incorporating molecularly imprinted polymers for mannose and magnetic iron oxide nanoparticles conjugated with BanLec. The biosensors were tested with HT-29 colorectal adenocarcinoma cells at different concentrations. Characterization of LIG sensors revealed an electroactive area of 6.06 mm², superior to the geometric area of 2.95 mm², confirming the characteristic porous structure of the material. The sensor functionalized with BanLec demonstrated specificity for mannose and detected HT-29 cells with a detection limit of 4.9 cells/μL and quantification limit of 16.3 cells/μL. The hybrid MIP/Fe₂O₃/BanLec system presented superior performance, achieving a detection limit of 4.16 cells/μL for HT-29 cells and 2.31 μM for mannose. The development of LIG-based biosensors functionalized with BanLec lectin demonstrated viability for detecting tumor cells through recognition of characteristic glycosylation alterations. The hybrid system presented the best analytical performance, combining synthetic recognition, magnetic amplification, and biological specificity. The results evidence the potential of the developed biosensors for future applications in noninvasive oncological diagnosis, especially in the context of liquid biopsy for early detection of colorectal cancer and other neoplasms that present altered glycosylation patterns.