Integrating Photothermal Effect and Peroxidase-Like Activity of Inorganic/Organic Nanocomposite to Advance Photothermometric Cholesterol Sensing Performance

Photothermometric sensors with a portable thermometer signal reader have been extensively used in the field of point-of-care testing (POCT) due to their simplicity, low cost and practicability. However, a long-standing challenge of low sensitivity greatly limit the development and application of these assays, especially for the most of nanozymes-based sensing systems. We herein demonstrated an enhanced photothermometric cholesterol (CHOL) sensor by integrating the photothermal effect and peroxidase-like activity of inorganic/organic nanocomposite. In this design, CHOL could selectively and firmly bind with PB@PDA@β-CD inorganic/organic nanoprobe, not only inhibiting the photothermal response of PB@PDA@β-CD, but also suppressing the peroxidase-like activity of PB@PDA@β-CD, resulting in a significant decrease on the photothermal response of nanozymes catalyzed oxTMB. It helps us to successfully develop a novel photothermometric strategy with a dual-signal transduction channels that originating from the inherent photothermal property and the peroxidase-like activity of PB@PDA@β-CD nanoprobe. We therefore reported a simple, rapid and signal-amplified photothermometric CHOL sensor with a satisfying LOD of 0.15 μM (S/N=3), which can meet the demand of CHOL detection in the serum samples, and has potential application in early diagnosis and quantitative analysis of disease.