MoS₂-ReS₂ Heterojunctions From A Bimetallic Co-chamber Feeding Atomic Layer Deposition For Biomolecular Detection

Photoelectrochemical biosensor（PEC）is a new technology for biomolecule detection,which has the advantages of low noise and low detection limit.Among the researches of PEC,photo active materials play an important role in PEC.In this paper,based on atomic layer deposition（ALD）technology,the design and construct of bimetallic co-chamber feeding ALD system were completed.Molybdenum disulfide-rhenium disulfide heterojunction electrode（MoS₂-ReS₂）was fabricated for the detection of micro RNA-21（mi RNA-21）.The main research contents are as follows:（1）Design,construct and process research of bimetallic co-chamber feeding ALD system.Independently designed and built a bimetallic co-chamber feeding ALD system,which is based on the self-limiting reaction mechanism of atomic layer deposition technology,combined with the overall structure of commercial ALD,and added multiple source pipelines and automated controls.The function enables the bimetallic co-chamber feeding ALD system to be more flexible and more accurate using atomic layer deposition technology to achieve experimental purposes according to experimental needs.（2）Controllable MoS₂-ReS₂ heterojunction manufacturing based on a bimetallic co-chamber feeding ALD system.Using a bimetallic co-chamber feeding ALD system,pure MoS₂,ReS₂ and MoS₂-ReS₂ heterojunction substrates were prepared respectively,and it was found that the heterojunction materials have better conductivity and stronger photosensitivity than pure semiconductor materials.And based on the self-limiting reaction principle of atomic layer deposition,the purpose of controlling the Mo/Re ratio in the material can be achieved by controlling the cycle ratio.By optimizing the cycle ratio,the optimal cycle ratio was found.Under this ratio,the heterojunction has the best conductivity and photosensitivity.These results together prove that the bimetallic co-chamber feeding ALD system is a flexible and accurate ALD device,and the semiconductor heterojunction prepared by the bimetallic co-chamber feeding ALD system is a very excellent photoelectric sensor material.（3）Performance optimization and biomolecule detection based on MoS₂-ReS₂heterojunction electrode.The photoelectrochemical sensor was constructed based on the heterojunction prepared with the optimal cycle ratio,and the mechanism of photoelectrochemical detection of biomolecule mi RNA-21 was analyzed.In the best experimental environment,the photoelectrochemical sensor can detect mi RNA-21 in the range of1×10^-17 M to 1×10^-9 M,with a minimum detection limit of 2.8 a M.Moreover,the photoelectrochemical sensor showed good sensitivity,selectivity,repeatability and stability,and the serum sample experiment also proved the potential application value of the detection electrode.