| Surface-enhanced Raman scattering（SERS）has received extensive attention in the field of biological detection due to its unique fingerprint characteristics and single-molecule sensitivity.Among them,"hotspots"play a vital role in SERS detection.This paper is based on the atomic layer deposition（ALD）technology to accurately prepare the SERS substrate Cd S/Mo S2@Au NPs which contains numerous highly active hotspots and can effectively capture the target molecule.The main research contents are as follows:（1）Cd S/Mo S2@Au NPs nano-array manufacturing based on ALD technology.Cd S/Mo S2@Au NPs nanoarrays were prepared using ALD technology and sacrificial template method,and a series of composition and morphology characterization analyses were performed on the samples.The study found that the active regulation of the size and distribution density of Au NPs can be achieved by controlling the electrochemical deposition time,and the distance between the nanopillars can be precisely controlled by controlling the number of ALD cycles,thereby ensuring the fine construction of"hotspots".（2）Research on SERS performance of Cd S/Mo S2@Au NPs.SERS performance experiments were carried out on substrates with different electrodeposition times and ALD cycles.It was found that when the deposition time was 7 minutes and the cycle number was95,the optimal 8 nm gap was obtained,and the SERS performance was improved by 9.4times compared with the control group.Among them,ALD technology has realized the construction of a large number of high-intensity"hotspots",which directly improves the SERS performance of the substrate;on the other hand,the 8 nm gap slightly larger than the analyte generates considerable capillary force,which makes the analyte it is easier to be captured and anchored more stably in the high charge density area simulated by the finite time domain-difference（FDTD）,so that the"hotspots"has a higher degree of self-activation.In addition,Mo S2 is more conducive to the electron transfer between the substrate and the analyte by adjusting the energy band structure.（3）Ultrasensitive SERS detection based on Cd S/Mo S2@Au NPs.The SERS sensor platform was constructed by using the nano-array with the optimal electrodeposition time and the number of ALD cycles as the substrate.Under the best experimental conditions,the SERS sensor can detect mi RNA-182 in the range of 1×10-17 M to 1×10-8 M,with a minimum detection limit of 0.82 a M.In addition,the SERS sensor shows good sensitivity,specificity and stability,and the serum sample experiment also shows the potential clinical application value of the SERS platform. |
PDF Full Text Request