High-sensitivity and high-specificity optical fiber SPR doxorubicin sensor enabled by Ti₃C₂ MXene sensitization

Doxorubicin, as an anthracycline antibiotic, is a commonly used and effective chemotherapeutic agent for treating various malignancies. However, it has a narrow therapeutic window. Therefore, real-time monitoring of doxorubicin concentration in chemotherapy patients is essential for enhancing treatment efficacy, minimizing side effects, and ensuring patient safety. In this paper, we proposed a Ti₃C₂ MXene-sensitized fiber surface plasmon resonance (SPR) doxorubicin sensor. By covalently functionalizing the reflective SPR sensing structure with Ti₃C₂ MXene, the refractive index sensitivity increased by 60.0 %. Furthermore, by covalently modifying the doxorubicin-specific aptamer, the sensor achieves high sensitivity and high specificity in the detection of doxorubicin. Within the linear range of 10-100 μM, it demonstrates a sensitivity of 0.24 nm/μM and a limit of detection of 2.79 μM. Furthermore, experiments confirmed that the doxorubicin sensor exhibits excellent specificity and can be applied for the detection of doxorubicin in real serum samples. The proposed doxorubicin sensor offers benefits such as high sensitivity, high specificity, fast response, and small size, and has the potential to meet the clinical requirements for monitoring doxorubicin concentration in chemotherapy patients.