Multivalent bifunctional nanobody to enhance the sensitivity of direct competitive chemiluminescence immunoassay for the detection of microcystin LR in lake water.

Microcystin-LR (MC-LR), a toxic cyanobacterial toxin in freshwater, poses significant health and ecological risks due to its ability to induce cell apoptosis and liver damage. Sensitive detection of MC-LR is crucial for public health and water safety. In this work, we engineered a multivalent bifunctional nanobody (A2.

Preparation of Mechanically Stable Self-Assembled Peptides Hydrogels.

Peptide hydrogels are highly hydrophilic, three-dimensional network gels formed by the self-assembly of nanofibers or polymers, creating water-locking networks. Their morphology closely resembles that of the extracellular matrix, allowing them to exhibit both the biological functions of peptides and responsive gelation properties. These unique characteristics have led to their extensive application in tissue engineering, three-dimensional cell culture, cancer therapy, regenerative medicine, and other biomedical fields.

In Situ High-Precision Measurement of Deep-Sea Dissolved Methane by Quartz-Enhanced Photoacoustic and Light-Induced Thermoelastic Spectroscopy.

Rapid and accurate realization of in situ analysis of deep-sea dissolved gases imperative to the study of ecological geology, oil and gas resource exploration, and global climate change. Herein, we report for the first time the deep-sea dissolved methane (CH) in situ sensor based on quartz-enhanced photoacoustic and light-induced thermoelastic spectroscopy. The developed sensor system has a volume of φ120 mm × 430 mm and a power consumption of 7.

Sub-ppt level detection of carbon monoxide and nitrous oxide enabled by mid-infrared doubly resonant photoacoustic spectroscopy.

We report highly sensitive detection of carbon monoxide (CO) and nitrous oxide (NO) using doubly resonant photoacoustic spectroscopy paired with a quantum cascade laser (QCL) at 4.57 μm. The butterfly-packaged QCL is used to exploit the CO absorption line at 2190.

Gel-to-Solution Transition of Sulfhydryl Self-Assembled Peptide Hydrogels Undergoing Oxidative Modulation.

The design of self-assembling biomaterials needs to take into consideration the timing and location of the self-assembly process. In recent decades, the principal strategy has been to control the peptide self-assembly under specific conditions to enable its functional performance. However, few studies have explored the responsive elimination of functional self-assembled peptide hydrogels after their function has been performed.

Frequency-Domain Detection for Frequency-Division Multiplexing QEPAS.

To achieve multi-gas measurements of quartz-enhanced photoacoustic spectroscopy (QEPAS) sensors under a frequency-division multiplexing mode with a narrow modulation frequency interval, we report a frequency-domain detection method. A CH absorption line at 1653.72 nm and a CO absorption line at 2004.

A Fiber-Integrated CRDS Sensor for In-Situ Measurement of Dissolved Carbon Dioxide in Seawater.

Research on carbon dioxide (CO) geological and biogeochemical cycles in the ocean is important to support the geoscience study. Continuous in-situ measurement of dissolved CO is critically needed. However, the time and spatial resolution are being restricted due to the challenges of very high submarine pressure and quite low efficiency in water-gas separation, which, therefore, are emerging the main barriers to deep sea investigation.

Investigation and Optimization of a Line-Locked Quartz Enhanced Spectrophone for Rapid Carbon Dioxide Measurement.

We have developed a rapid quartz enhanced spectrophone for carbon dioxide (CO) measurement, in which the laser wavelength was tightly locked to a CO absorption line and a custom quartz tuning fork (QTF) operating at 12.5 kHz was employed. The intrinsic QTF oscillation-limited response time, as well as the optimal feedback interval, was experimentally investigated.

Development of a laser heterodyne spectroradiometer for high-resolution measurements of CO, CH, HO and O in the atmospheric column.

We have developed a portable near-infrared laser heterodyne radiometer (LHR) for quasi-simultaneous measurements of atmospheric carbon dioxide (CO), methane (CH), water vapor (HO) and oxygen (O) column absorption by using three distributed-feedback diode lasers as the local oscillators of the heterodyne detection. The developed system shows good performance in terms of its high spectral resolution of 0.066 cm and a low solar power detection noise which was about 2 times the theoretical quantum limit.

A Robust Optical Sensor for Remote Multi-Species Detection Combining Frequency-Division Multiplexing and Normalized Wavelength Modulation Spectroscopy.

By combining frequency-division multiplexing and normalized wavelength modulation spectroscopy, a robust remote multi-species sensor was developed and demonstrated for practical hydrocarbon monitoring. Independently modulated laser beams are combined to simultaneously interrogate different gas samples using an open-ended centimeter-size multipass cell. Gas species of interest are demodulated with the second harmonics to enhance sensitivity, and high immunity to laser power variation is achieved by normalizing to the corresponding first harmonics.

Development of an in situ analysis system for methane dissolved in seawater based on cavity ringdown spectroscopy.

This paper reports the development of a compact in situ real-time concentration analysis system for methane dissolved in seawater by using a continuous-wave cavity ringdown spectroscopy (CRDS) technique. The miniaturized design of the system, including optical resonance cavity and control and data acquisition-analysis electronics, has a cylindrical dimension of 550 mm in length and 100 mm in diameter. Ringdown signal generation, data acquisition and storage, current driver, and temperature controller of the diode laser are all integrated in the miniaturized system circuits, with an electrical power consumption of less than 12 W.

Compact Open-Path Sensor for Fast Measurements of CO and HO using Scanned-Wavelength Modulation Spectroscopy with -Phase Method.

We report here the development of a compact, open-path CO and HO sensor based on the newly introduced scanned-wavelength modulation spectroscopy with the first harmonic phase angle (scanned-WMS-θ) method for high-sensitivity, high temporal resolution, ground-based measurements. The considerable advantage of the sensor, compared with existing commercial ones, lies in its fast response of 500 Hz that makes this instrument ideal for resolving details of high-frequency turbulent motion in exceptionally dynamic coastal regions. The good agreement with a commercial nondispersive infrared analyzer supports the utility and accuracy of the sensor.

Simultaneous measurement of gas absorption and path length by employing the first harmonic phase angle method in wavelength modulation spectroscopy.

Tunable diode laser absorption spectroscopy has been widely employed for gas sensing, where the gas concentration is often obtained from the absorption signal with a known or a fixed absorption path length. Nevertheless, there are also numerous applications in which the absorption path length is very challenging to retrieve, e.g.

Development of a compact tunable diode laser absorption spectroscopy based system for continuous measurements of dissolved carbon dioxide in seawater.

Robust marine carbon sensors with small size, low power consumption, and high sensitivity provide greater insight into the carbon cycle studies and resolve environmental variability. We report here the development of a diminutively integrated tunable diode laser absorption spectroscopy (TDLAS) system with a specially designed multipass gas cell for small amounts of dissolved gas extractions and measurements. It was used to detect and monitor carbon dioxide (CO) dissolved in water and seawater.

SMAD4 is required for development of maximal endotoxin tolerance.

Initial exposure of monocytes/macrophages to LPS induces hyporesponsiveness to a second challenge with LPS, a phenomenon termed LPS tolerance. Molecular mechanisms responsible for endotoxin tolerance are not well defined. We and others have shown that IL-1R-associated kinase (IRAK)-M and SHIP-1 proteins, negative regulators of TLR4 signaling, increase in tolerized cells.