Next Article in Journal
A Plasmid-Encoded FetMP-Fls Iron Uptake System Confers Selective Advantages to Salmonella enterica Serovar Typhimurium in Growth under Iron-Restricted Conditions and for Infection of Mammalian Host Cells
Previous Article in Journal
Exploring Coagulase-Negative Staphylococci Diversity from Artisanal Llama Sausages: Assessment of Technological and Safety Traits
Article

Bacterial Synthesis of Ternary CdSAg Quantum Dots through Cation Exchange: Tuning the Composition and Properties of Biological Nanoparticles for Bioimaging and Photovoltaic Applications

1
BioNanotechnology and Microbiology Lab, Center for Bioinformatics and Integrative Biology (CBIB), Facultad de Ciencias de la Vida, Universidad Andrés Bello, Av. República #330, Santiago 8370186, Chile
2
Institute for Lasers, Photonics and Biophotonics, University at Buffalo, Buffalo, NY 14260, USA
3
Laboratorio de Nanotecnología, Recursos Naturales y Sistemas Complejos, Facultad de Ciencias Naturales, Departamento de Química y Biología, Universidad de Atacama, Copayapu 485, Copiapó 1531772, Chile
4
Laboratorio de Microbiología Oral, Facultad de Odontología, Universidad de Chile, Sergio Livingstone Pohlhammer # 943, Santiago 8380492, Chile
5
Molecular and Cellular Virology Laboratory, Virology Program, Institute of Biomedical Sciences, Faculty of Medicine, Universidad of Chile, Independencia, Santiago 834100, Chile
*
Authors to whom correspondence should be addressed.
Microorganisms 2020, 8(5), 631; https://doi.org/10.3390/microorganisms8050631
Received: 7 February 2020 / Revised: 13 March 2020 / Accepted: 24 March 2020 / Published: 27 April 2020
(This article belongs to the Section Microbial Biotechnology)
In this study, we introduce a biological method for the production of ternary Quantum Dots (QDs): complex nanostructures with tunable optical and structural properties that utilizes post-synthesis modifications through cation exchange. This versatile in-situ cation exchange method being reported for the first time shows great potential for extending the scope of microbial synthesis. By using this bacterial-based method, we easily synthesize and purify CdS, CdSAg, and Ag2S nanocrystals of a size below 15 nm and with variable morphologies that exhibit fluorescence emissions covering a broad spectral range (from 400 to 800 nm). Energy-dispersive X-ray spectroscopy (EDS) results indicate the partial replacement of Cd2+ by Ag+ when AgNO3 concentration is increased. This replacement produces CdSAg ternary QDs hetero-structures with high stability, fluorescence in the NIR-I (700 - 800 nm), and 36.13% quantum yield. Furthermore, this reaction can be extended for the production of soluble Ag2S nanoparticles (NPs) without any traces of Cd. QDs biosynthesized through this cation exchange process display very low toxicity when tested in bacterial or human cell lines. Biosynthesized ternary hetero-structures were used as red fluorescent dyes to label HeLa cells in confocal microscopy studies, which validates its use in bioimaging applications in the near infrared region. In addition, the application of biologically-produced cadmium NPs in solar cells is reported for the first time. The three biosynthesized QDs were successfully used as photosensitizers, where the CdSAg QDs show the best photovoltaic parameters. Altogether, obtained results validate the use of bacterial cells for the controlled production of nanomaterials with properties that allow their application in diverse technologies. We developed a simple biological process for obtaining tunable Quantum Dots (QDs) with different metal compositions through a cation exchange process. Nanoparticles (NPs) are produced in the extracellular space of bacterial cells exposed to cysteine and CdCl2 in a reaction that depends on S2− generation mediated by cysteine desulfhydrase enzymes and uses cellular biomolecules to stabilize the nanoparticle. Using this extracellular approach, water-soluble fluorescent CdS, CdSAg, and Ag2S Quantum Dots with a tunable emission ranging from 400 to 800 nm were generated. This is the first study reporting the use of microorganisms to produce tunable ternary QDs and the first time that a cation exchange process mediated by cells is described. Obtained results validate the use of biological synthesis to produce NPs with new characteristics and opens a completely new research field related to the use of microorganisms to synthesize complex NPs that are difficult to obtain with regular chemical methods. View Full-Text
Keywords: ionic exchange; tunable nanoparticles; aqueous synthesis; nanoparticle biosynthesis ionic exchange; tunable nanoparticles; aqueous synthesis; nanoparticle biosynthesis
Show Figures

Graphical abstract

MDPI and ACS Style

Órdenes-Aenishanslins, N.; Anziani-Ostuni, G.; Monrás, J.P.; Tello, A.; Bravo, D.; Toro-Ascuy, D.; Soto-Rifo, R.; Prasad, P.N.; Pérez-Donoso, J.M. Bacterial Synthesis of Ternary CdSAg Quantum Dots through Cation Exchange: Tuning the Composition and Properties of Biological Nanoparticles for Bioimaging and Photovoltaic Applications. Microorganisms 2020, 8, 631. https://doi.org/10.3390/microorganisms8050631

AMA Style

Órdenes-Aenishanslins N, Anziani-Ostuni G, Monrás JP, Tello A, Bravo D, Toro-Ascuy D, Soto-Rifo R, Prasad PN, Pérez-Donoso JM. Bacterial Synthesis of Ternary CdSAg Quantum Dots through Cation Exchange: Tuning the Composition and Properties of Biological Nanoparticles for Bioimaging and Photovoltaic Applications. Microorganisms. 2020; 8(5):631. https://doi.org/10.3390/microorganisms8050631

Chicago/Turabian Style

Órdenes-Aenishanslins, Nicolás, Giovanna Anziani-Ostuni, Juan P. Monrás, Alejandra Tello, Denisse Bravo, Daniela Toro-Ascuy, Ricardo Soto-Rifo, Paras N. Prasad, and José M. Pérez-Donoso 2020. "Bacterial Synthesis of Ternary CdSAg Quantum Dots through Cation Exchange: Tuning the Composition and Properties of Biological Nanoparticles for Bioimaging and Photovoltaic Applications" Microorganisms 8, no. 5: 631. https://doi.org/10.3390/microorganisms8050631

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop