Temperature induced size selective synthesis of hybrid Cds/pepsin nanocrystals and their photoluminescence investigation

Toward Biocompatible Semiconductor Quantum Dots: From Biosynthesis and Bioconjugation to Biomedical Application

“…The use of ribonuclease-A as the template may not only endow the QDs with good biocompatibility but also decrease the cytotoxicity of QDs. , In addition, ribonuclease-A has excellent thermal stability, enabling simple regulation of QD emission by controlling the reaction time and temperature. Pepsin and luciferase can be employed as the matrix for the synthesis of various QDs as well. − Pepsin is particularly rich in aspartic acid residues at the active site (aspartic acid plays important roles in biomineralization in biological systems), which may coordinate with cadmium ions and provide a nucleation site for the growth of QDs. In particular, the coordination between pepsin and cadmium ions may induce a conformational change of pepsin from α-helix to β-sheet, facilitating the oriented growth of CdS QDs .…”

“…In particular, the coordination between pepsin and cadmium ions may induce a conformational change of pepsin from α-helix to β-sheet, facilitating the oriented growth of CdS QDs . In addition, the size and optical properties of CdS QDs may be tuned by simply adjusting the reaction temperature . The size of CdS QDs may increase from 1.7 to 5.2 nm with a gradual increase in the reaction temperature from 4 to 45 °C.…”

“…Interestingly, pepsin becomes more folded at lower temperature, enabling the attachment of more pepsins to reduce the surface traps of QDs. As a result, the QDs obtained at 4 °C display the highest emission efficiency in the violet region . Similarly, luciferase (Luc8) can bind Pb 2+ to form the Luc8-Pb 2+ complex, which in turn serves as a nucleation site for the growth of NIR PbS QDs in the presence of S 2– (Figure ).…”

“…127 In addition, the size and optical properties of CdS QDs may be tuned by simply adjusting the reaction temperature. 126 The size of CdS QDs may increase from 1.7 to 5.2 nm with a gradual increase in the reaction temperature from 4 to 45 °C. Interestingly, pepsin becomes more folded at lower temperature, enabling the attachment of more pepsins to reduce the surface traps of QDs.…”

Metal–Protein Hybrid Materials with Desired Functions and Potential Applications

“…The emission wavelength of quantum dots can be simply tuned through controlling the reaction time and temperature. , The use of Ribonuclease-A (RNase-A) as a biotemplate may endow the quantum dots with excellent optical properties and good biocompatibility. Pepsin and luciferase have been also extensively utilized as the protein matrix for the design and synthesis of various quantum dots. − The synthesis of quantum dots through protein biotemplates has also been demonstrated. Goldman et al used avidin as a linker protein to prepare antibody-QD .…”