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Jakhmola A, Vecchione R, Onesto V, Gentile F, Celentano M, Netti PA. Experimental and Theoretical Studies on Sustainable Synthesis of Gold Sol Displaying Dichroic Effect. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:236. [PMID: 33477466 PMCID: PMC7830637 DOI: 10.3390/nano11010236] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 01/14/2021] [Accepted: 01/14/2021] [Indexed: 11/23/2022]
Abstract
Gold nanoparticles depending on their shape and mixtures of multiple shapes can exhibit peculiar optical properties, including the dichroic effect typical of the Lycurgus cup, which has puzzled scientists for a long time. Such optical properties have been recently exploited in several fields such as paint technology, sensors, dichroic polarizers, display (LCD) devices, laser applications, solar cells and photothermal therapy among others. In this article, we have demonstrated a simple room temperature one-pot synthesis of gold sol displaying a dichroic effect using a slow reduction protocol involving only trisodium citrate as a reducing agent. We found that the dichroic gold sol can be easily formed at room temperature by reducing gold salt by trisodium citrate below a certain critical concentration. The sol displayed an orangish-brown color in scattered/reflected light and violet/blue/indigo/purple/red/pink in transmitted light, depending on the experimental conditions. With minor changes such as the introduction of a third molecule or replacing a small amount of water in the reaction mixture with ethanol, the color of the gold sol under transmitted light changed and a variety of shades of red, pink, cobalt blue, violet, magenta and purple were obtained. The main advantage of the proposed method lies in its simplicity, which involves the identification of the right ratio of the reactants, and simple mixing of reactants at room temperature with no other requirements. TEM micrographs displayed the formation of two main types of particles viz. single crystal gold nanoplates and polycrystalline faceted polyhedron nanoparticles. The mechanism of growth of the nanoplates and faceted polyhedron particles have been described by an enhanced diffusion limited aggregation numerical scheme, where it was assumed that both trisodium citrate and the gold ions in solution undergo a stochastic Brownian motion, and that the evolution of the entire system is regulated by a principle of energy minimization. The predictions of the model matched with the experiments with a good accuracy, indicating that the initial hypothesis is correct.
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Affiliation(s)
- Anshuman Jakhmola
- Istituto Italiano di Tecnologia, IIT@CRIB, Largo Barsanti e Matteucci 53, 80125 Napoli, Italy; (M.C.); (P.A.N.)
| | - Raffaele Vecchione
- Istituto Italiano di Tecnologia, IIT@CRIB, Largo Barsanti e Matteucci 53, 80125 Napoli, Italy; (M.C.); (P.A.N.)
- Centro di Ricerca Interdipartimentale sui Biomateriali CRIB, Università di Napoli Federico II, Piazzale Tecchio 80, 80125 Napoli, Italy
| | - Valentina Onesto
- CNR NANOTEC—Institute of Nanotechnology c/o Campus Ecotekne, via Monteroni, 73100 Lecce, Italy;
| | - Francesco Gentile
- Department of Electric Engineering and Information Technology, University Federico II, 80125 Naples, Italy
- Department of Experimental and Clinical Medicine, University Magna Graecia, 88100 Catanzaro, Italy
| | - Maurizio Celentano
- Istituto Italiano di Tecnologia, IIT@CRIB, Largo Barsanti e Matteucci 53, 80125 Napoli, Italy; (M.C.); (P.A.N.)
- School of Chemistry and Chemical Engineering, University Belfast, David Keir Building, 39-123 Stranmillis Rd, Belfast BT9 5AG, Northern Ireland, UK
| | - Paolo Antonio Netti
- Istituto Italiano di Tecnologia, IIT@CRIB, Largo Barsanti e Matteucci 53, 80125 Napoli, Italy; (M.C.); (P.A.N.)
- Centro di Ricerca Interdipartimentale sui Biomateriali CRIB, Università di Napoli Federico II, Piazzale Tecchio 80, 80125 Napoli, Italy
- Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, Piazzale Tecchio 80, 80125 Napoli, Italy
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Jakhmola A, Vecchione R, Onesto V, Gentile F, Profeta M, Battista E, Manikas AC, Netti PA. A theoretical and experimental study on l-tyrosine and citrate mediated sustainable production of near infrared absorbing twisted gold nanorods. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2021; 118:111515. [DOI: 10.1016/j.msec.2020.111515] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 08/18/2020] [Accepted: 09/04/2020] [Indexed: 11/29/2022]
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