title: Facile green extracellular biosynthesis of CdS quantum dots by white rot fungus Phanerochaete chrysosporium.
abstract: This study details a novel method for the extracellular microbial synthesis of cadmium sulfide (CdS) quantum dots (QDs) by the white rot fungus Phanerochaete chrysosporium. P. chrysosporium was incubated in a solution containing cadmium nitrate tetrahydrate, which became yellow from 12h onwards, indicating the formation of CdS nanocrystals. The purified solution showed a maximum absorbance peak between 296 and 298 nm due to CdS particles in the quantum size regime. The fluorescence emission at 458 nm showed the blue fluorescence of the nanoparticles. X-ray analysis of the nanoparticles confirmed the production of CdS with a face-centered cubic (fcc) crystal structure. The average grain size of the nanoparticles was approximately 2.56 nm, as determined from the full width at half-maximum (FWHM) measurement of the most intense peak using Scherer's equation. Transmission electron microscopic analysis showed the nanoparticles to be of a uniform size with good crystallinity. The changes to the functional groups on the biomass surface were investigated through Fourier transform infrared spectroscopy. Furthermore, the secretion of cysteine and proteins was found to play an important role in the formation and stabilization of CdS QDs. In conclusion, our study outlines a chemical process for the molecular synthesis of CdS nanoparticles.
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China. Electronic address: gqchen@hnu.edu.cn.
authors.forename: Guiqiu
authors.initials: G
authors.lastname: Chen
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
authors.forename: Bin
authors.initials: B
authors.lastname: Yi
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China. Electronic address: zgming@hnu.edu.cn.
authors.forename: Guangming
authors.initials: G
authors.lastname: Zeng
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
authors.forename: Qiuya
authors.initials: Q
authors.lastname: Niu
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
authors.forename: Ming
authors.initials: M
authors.lastname: Yan
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
authors.forename: Anwei
authors.initials: A
authors.lastname: Chen
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
authors.forename: Jianjian
authors.initials: J
authors.lastname: Du
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
authors.forename: Jian
authors.initials: J
authors.lastname: Huang
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
authors.forename: Qihua
authors.initials: Q
authors.lastname: Zhang
mesh_terms: D019187:Cadmium Compounds / Q000378:metabolism*; D004055:Differential Thermal Analysis; D005110:Extracellular Space / Q000378:metabolism*; D055772:Green Chemistry Technology / Q000379:methods*; D053758:Nanoparticles / Q000648:ultrastructure; D020075:Phanerochaete / Q000378:metabolism*; D045663:Quantum Dots / Q000378:metabolism* / Q000648:ultrastructure; D013052:Spectrometry, X-Ray Emission; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013440:Sulfides / Q000378:metabolism*; D013818:Thermogravimetry; D014961:X-Ray Diffraction
chemical_list: D019187:Cadmium Compounds; D013440:Sulfides; C034939:cadmium sulfide
keywords: Biosynthesis; CdS; Face-centered cubic; Nanoparticles