An rGO-doped laser induced graphene electrochemical biosensor for highly sensitive exosome detection

In this study, we developed a novel electrochemical sensing chip integrated with reduced graphene oxide (rGO) with laser-induced graphene (LIG) for the detection of exosomes associated with breast cancer biomarkers. Employing laser-induced technology, a three-dimensional porous graphene material is fabricated on the surface of a flexible polyimide film, which is subsequently combined with rGO through π–π stacking. This integration facilitates the doping of two-dimensional and three-dimensional material (2D/3D) structures, significantly enhancing the conductivity of the electrode material. Additionally, this approach markedly improves the surface hydrophobicity and biomolecule affinity of LIG, optimizing the immobilization of specific antibodies for exosomes. Importantly, this experiment marks the first occasion of merging two-dimensional rGO with three-dimensional LIG, resulting in the construction of a high-performance biosensing chip that enables specific capture and highly sensitive detection of exosomes. Under optimized conditions, the quantitative detection range for exosomes is established at 5 × 10² to 5 × 10⁵ particles per μL, with a limit of detection (LOD) of 166 particles per μL. The biosensor is successfully used to analyze exosomes in breast cancer cell lines and patient serum samples, proving its practical application. This electrochemical biosensing chip offers significant practical application value in the early screening and diagnosis of diseases.