A Signal‐Switchable Fluorescent‐Colorimetric Dual‐Signal Probe for Detection of Sunitinib Based on D‐Penicillamine‐Functionalized Silicon Nanoparticles

ABSTRACT Sunitinib (SNTN), a multi‐target receptor tyrosine kinase (RTK) inhibitor, plays a significant role in the clinical treatment of renal cell carcinoma (RCC). However, drug resistance to this agent severely restricts its long‐term clinical efficacy. Therefore, the development of a precise platform for SNTN monitoring has become an important research direction. In this study, D‐penicillamine‐functionalized silicon nanoparticles (DPA‐SiNPs) with low toxicity and excellent photostability were synthesized via the hydrothermal method, using N‐(2‐aminoethyl)‐3‐aminopropyltriethoxysilane (AEAPTMS) and D‐penicillamine (DPA) as raw materials. Subsequently, DPA‐SiNPs were used as a dual‐signal sensor probe for fluorescence and colorimetry. SNTN quenches the fluorescence and UV–Vis absorption signals of DPA‐SiNPs via the internal filtration effect (IFE). Based on this mechanism, a dual‐signal detection system was established. The limits of detection for fluorescence and colorimetric dual‐signal sensing were as low as 0.13 nM and 0.16 μM ( S / N = 3), with good linear relationships in the ranges of 0.87–790.03 nM (R 2 = 0.992) and 3.95–76.30 μM ( R 2 = 0.992), respectively.