Archive: October 21, 2022

Congratulations for our new paper in Journal of Optics Communications

Highly sensitive surface plasmon resonance sensor for detection of Methylene Blue and Methylene Orange dyes using NiCo-Layered Double Hydroxide

Amir RezaSadrolhosseini, EbrahimGhasami, AzamPirkarimi, Seyedeh MehriHamidi, RezaTaheri Ghahrizjani

Surface plasmon resonance (SPR) sensor is a versatile technique to detect toxic materials in the environment. In this study, the SPR technique was used to detect the environmental contaminant dyes such as methylene blue (MB) and methylene orange (MO). The surface of the gold layer was modified using NiCo-layered double hydroxide (LDH) which was fabricated with the electrodeposition method and characterized using field emission scanning electron microscopy, X-ray diffraction spectroscopy, and transmission electron microscopy. The thickness of LDH was controlled by deposition time and a homogeneous coating of LDH was obtained in the short time range of less than 150s. The adsorption of MB and MO on LDH was studied using the SPR technique based on angular modulation. Langmuir adsorption isotherm was fitted for data of adsorbents and the adsorption mechanism was described. The sensor limit and the response time were about 0.005 ppm and 268 s, respectively. It was proved that the sensitivity of the sensor can be controlled by the thickness of the LDH layer. Results indicated that the glass/Au/ NiCo-LDH system is fast and efficient for the detection of the MB and MO dyes in a short time.

News On Quantum Sensing

Engineering atomic antennas for quantum sensing

Jennifer Choy makes atom-size antennas. They bear no resemblance to the telescoping rod that transmits pop hits through a portable stereo. But functionally, they’re similar. They’re quantum sensors, picking up tiny electromagnetic signals and relaying them in a way we can measure.

How tiny a signal? A quantum sensor could discern temperature changes in a single cell of human tissue or even magnetic fields originating at Earth’s core.

Jennifer Choy, a scientist at the University of Wisconsin–Madison, is developing technologies that could lead to ultraprecise accelerometers and magnetometers for navigation and for probing minuscule changes in a material’s electromagnetic fields.

“You can think of these quantum sensors as an atomic scale probe that allows you to be sensitive to and measure really localized changes in magnetic fields,” Choy said. “And you can extend your measurements to probe macroscopic magnetic features and other physical parameters like mechanical strain and temperature.”

Taking advantage of atoms’ quantum nature—which reveals itself only at nature’s smallest scales—and their sensitivity to external disturbances, these sensors exhibit extraordinary accuracy and precision, making their traditional counterparts look like blunt instruments by comparison.

For Choy, the challenge is to boost the efficiency with which these invisible instruments transmit information. The research is equal parts physics discovery and engineering, she says.

“I find the work exciting because it’s a good fit for the kind of hodgepodge training that I had,” said Choy, who is a member of both Q-NEXT, a U.S. Department of Energy (DOE) National Quantum Information Science Research Center led by DOE’s Argonne National Laboratory, and the National Science Foundation’s Quantum Leap Challenge Institute for Hybrid Quantum Architectures and Networks, or HQAN. “I’m an applied physicist by training, and I don’t categorize myself as purely a physicist or engineer. But I really enjoy that intersection of fundamental science and engineering work.”

Light and matter

Choy works on quantum sensors in which electrons in quantum materials act as the antenna. The information they pick up can be read through their interactions with photons, the massless particles that carry electromagnetic information.

For more details, refer to the link below:

phys.org/news/2022-08-atomic-antennas-quantum.html

News On Bio-Contact Lenses

In this days, the Journal of ACS Appl. Polym. Mater. published a new paper entitled as “Pressure-Triggered Microfluidic Contact Lens for Ocular Drug Delivery”

Microfluidic technology has been used for precise drug delivery for many years, but microfluidic wearable devices have mostly been used for skin drug delivery. The application of eye drops is currently one of the most common ways to treat eye diseases. However, due to their low corneal bioavailability and short residence time in tears, topical eye drops must be applied multiple times a day. Contact lenses, as a wearable device for the eye, are a good platform for drug delivery. In this paper, we propose a type of microfluidic contact lens that integrates a microchannel and a micropump and uses a pressure source to trigger the release of a drug. Here, a flat microfluidic chip component is first fabricated by photolithography and then cast into a curved surface by secondary thermosetting. Through experiments, the outlet check valve opening pressure and liquid flow test were studied to prove that the liquid release is controllable. In addition, the microfluidic contact lens has good flexibility, light transmittance, and biocompatibility. Finally, we demonstrate through fluorescence experiments that the microfluidic contact lens can be loaded with different types of drugs in different regions. In general, liquid exchange between the eye and the contact lens can be realized through the mechanical action of blinking without using electronic components, meaning more safety and stability. The mechanical characteristics of a blink can be artificially regulated to a large extent; thus, it is also possible to achieve specific, personalized medicine.