Wyniki wyszukiwania - BazTech

1

Analysis of the Influence of an XY Electronic Mechanism with UV-Vis Spectroscopy on the Production of Gold Nanoparticles by Laser Ablation for Applications in Environmental Nanosensing

Carbajal-Morán Hipólito, Márquez-Camarena Javier F., Ingaruca-Álvarez Ever F., Zárate-Quiñones Rosa H.

Journal of Ecological Engineering

|

2023

|

Vol. 24, nr 8

52--61

EN

The work consisted in analyzing the influence of an electronic positioning mechanism of an Au metal plate in the XY axes; to optimize the production of Au metal nanoparticles by laser ablation in sterile water samples as well as to obtain morphology and size required for environmental nanosensors. The positioning mechanism is constituted by two M35SP stepper motors of 5 V DC with a rotation angle of 7.5° per step; the one that generates the displacement for each axis of XY coordinates, controlled by an algorithm implemented in Arduino Nano ATmega328, being the driver of the stepper motors the H-bridge of the L298N module, with which it was possible to set the speed to 2 mm/s, which enabled to make the wear of the metal plate uniform in the process of generation of gold nanoparticles (AuNPs). With the pulsed laser generator with ablation frequency of 10 Hz and wavelengths of 532 nm and 1064 nm, the Au metal plate was irradiated for 10 min, 20 min and 30 min. AuNPs were generated in colloidal state both for the process with fixed position of the metal plate and for the process using the electronic mechanism of XY positioning; they were characterized by UV-Vis spectroscopy with range from 300 nm to 850 nm. It was found that the production of AuNPs with the Au plates mobilized by the mechanism under study, generates colloids of spherical AuNPs of smaller diameter, close to 10 nm, with an average reduction of 19% in relation to that generated with the fixed position plate; likewise, the concentration of the AuNPs increased by 20.40%; therefore, the influence of the XY positioning electronic mechanism was positive in the production of AuNPs with morphology and sizes suitable for use in environmental nanosensors.

2

Metal nanoparticles in nanosensors for food quality assurance

Dobrucka Renata

LogForum

|

2020

|

Vol. 16, no. 2

271--278

EN

Background: Nanotechnology is applied in the food industry to ensure food safety, and it is used both in the processing of food and detection of contaminants. The assurance of quality and safety of food has become an important issue for authorities and food supply chain actors. In order to protect consumers from contamination, adulteration and spoilage, it is absolutely necessary to conduct analyses of food, as it is exposed to numerous chemical substances, which may be harmful to human beings and the environment. Methods: This work presents an overview of the literature concerning nanosensors with metal nanoparticles, which are used to detect the presence of chemical contaminants, pathogens and toxins, as well as to monitor food quality status. Such solutions will undoubtedly contribute to maintaining the safety and quality of food. Results and conclusion: At present, food supply chains are becoming more complex, environmental constraints are becoming stricter, and consumers are changing the way in which they select and consume food, and all those factors inspire modern societies to be more concerned about the harmful substances that could be present in food products. Application of nanoparticles in the food production industry are farreaching and more research in this space is warranted. As developments in the research and development of nanotechnologies continue, so will the opportunities for the food industry to benefit from nanoscience.

PL

Wstęp: Nanotechnologia jest stosowana w przemyśle spożywczym w celu zapewnienia bezpieczeństwa żywności i jest wykorzystywana zarówno w przetwórstwie żywności, jak i wykrywaniu zanieczyszczeń. Zapewnienie jakości i bezpieczeństwa żywności jest ważną kwestią w łańcuchu dostaw żywności. Aby chronić konsumentów przed skażeniem, zafałszowaniem i psuciem, absolutnie konieczne jest przeprowadzenie oceny jakości żywności, ze względu na narażenie na substancje, które mogą być szkodliwe dla ludzi i środowiska. Metody: W pracy przedstawiono przegląd literatury dotyczącej nanosensorów zawierających nanocząstki metali, które służą do wykrywania obecności zanieczyszczeń chemicznych, patogenów i toksyn, a także do monitorowania stanu jakości żywności. Takie rozwiązania niewątpliwie przyczynią się do utrzymania bezpieczeństwa i jakości żywności. Wyniki i podsumowanie: Obecnie łańcuchy dostaw żywności stają się coraz bardziej złożone, ograniczenia środowiskowe stają się coraz surowsze, a konsumenci zmieniają sposób, w jaki wybierają i spożywają żywność. Wszystkie te czynniki powodują zainteresowanie i coraz większą dbałość o jakość i bezpieczeństwo żywności. Zastosowanie nanocząstek w przemyśle spożywczym daje szerokie perspektywy, w związku z tym uzasadnione są dalsze badania w tym obszarze. Wraz z rozwojem badań i rozwoju nanotechnologii będą również rosnąć możliwości, jakie przemysł spożywczy może czerpać z nanonauki.

3

Dopant-Based Charge Sensing Utilizing P-I-N Nanojunction

Nowak R., Jabłoński R.

Metrology and Measurement Systems

|

2017

|

Vol. 24, nr 2

391--399

EN

We studied lateral silicon p-i-n junctions, doped with phosphorus and boron, regarding charge sensing feasibility. In order to examine the detection capabilities and underlying mechanism, we used in a complementary way two measurement techniques. First, we employed a semiconductor parameter analyzer to measure I−V characteristics at a low temperature, for reverse and forward bias conditions. In both regimes, we systematically detected Random Telegraph Signal. Secondly, using a Low Temperature Kelvin Probe Force Microscope, we measured surface electronic potentials. Both p-i-n junction interfaces, p-i and i-n, were observed as regions of a dynamic behaviour, with characteristic time-dependent electronic potential fluctuations. Those fluctuations are due to single charge capture/emission events. We found analytically that the obtained data could be explained by a model of two-dimensional p-n junction and phosphorus-boron interaction at the edge of depletion region. The results of complementary measurements and analysis presented in this research, supported also by the previous reports, provide fundamental insight into the charge sensing mechanism utilizing emergence of individual dopants.

4

Fabrication of electrochemical nanoelectrode for sensor application Rusing focused ion beam technology

Łaszcz A., Nogala W., Czerwinski A., Ratajczak J., Kątcki J.

Polish Journal of Chemical Technology

|

2014

|

Vol. 16, nr 3

40--44

EN

The capabilities and applications of the focused ion beam (FIB) technology for detection of an electrochemical signal in nanoscale area are shown. The FIB system, enabling continuous micro- and nanofabrication within only one equipment unit, was used to produce a prototype of electrochemical nanometer-sized electrode for sensor application. Voltammetric study of electrochemically active compound (ferrocenemethanol) revealed the diffusion limiting current (12 pA), corresponding to a disc (planar) nanoelectrode with about 70 nm diameter of contact area. This size is in a good accordance with the designed contact-area (50 nm × 100 nm for width × thickness) of the FIB-produced nanoelectrode. It confi rms that produced nanoelectrode is working properly in liquid solution and may enable correct measurements in nanometer-sized regions.