SERS and photoelectric conversion properties of cholesterol derivatives composite Langmuir-Blodgett films with dyes

Cholesterol derivatives play a vital role in various fields, including medicine, biology, and smart materials. The Langmuir-Blodgett (LB) technology uses molecular self-assembly to create interfacially organized thin film materials with unique characteristics. This work primarily used two cholesterol derivatives (CCA and CCH) coupled with various dyes to create multilayer composite LB films. The SERS test determined the enhancement factor EF=1.07×10 5 for the CCA/ST composite film and EF=1.12×10 5 for the CCH/ST multilayer composite films, with relative standard deviation RSD=12.58% and 3.86%, respectively. The result demonstrates the superior signal responsiveness and uniformity of the resultant LB films, offering a novel option for active substrate materials in SERS detection of trace compounds. The photoelectric response signal of the CCA/dye and CCH/dye composite LB films was demonstrated to be sensitive by the photoelectric conversion test, and the films' superior reusability was demonstrated by the persistence of the same pattern over several recurring cycles. It offers a novel idea for investigating the use of cholesterol derivatives in optoelectronic devices in more detail.