In this paper, we propose and experimentally demonstrate a symmetric multi-resonant cavity photoacoustic cell (MR-PAC) with dual microphones detection, based on multi-resonator photoacoustic spectroscopy (MR-PAS). The designed photoacoustic cell contains three interconnected acoustic resonators to facilitate simultaneous control of three lasers for multi-gas sensing. Two microphones are symmetrically located at both sides of photoacoustic cell to implement two-point detection. The length of acoustic resonator is about 50 mm to minimize the photoacoustic cell, and the resonant frequency is around 3000 Hz. Feasibility and performance of the MR-PAC was demonstrated by simultaneous detection of CH, NO and CF using a near infrared diode laser and two mid infrared quantum cascade lasers. The minimum detection limits (MDLs) of CH, NO and CF are 480 ppb, 260 ppb and 0.57 ppb respectively with a 1 s integration time at normal atmospheric pressure. This minimized MR-PAS system is promising for the portable multi-gas sensing.
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http://dx.doi.org/10.1016/j.pacs.2023.100526 | DOI Listing |
Anal Chem
January 2025
International Joint Laboratory for Integrated Circuits Design and Application, Ministry of Education, School of Physics, Zhengzhou University, Zhengzhou 450001, China.
The photoacoustic spectroscopy (PAS) system commonly enhances the efficiency of optical-acoustic-electrical energy conversion by increasing the laser power, optimizing the resonance characteristics of the photoacoustic cell (PAC), and improving the sensitivity of acoustic sensors. However, conventional systems using a single-microphone or a dual-microphone differential setup for point sampling of the photoacoustic signal fail to account for its spatial distribution, leading to a loss of spatial gain. Drawing on microphone array theory derived from sonar technology, this study, for the first time, presents a PAS sensing system based on a four-microphone array, which is applied to detect chloroform gas.
View Article and Find Full Text PDFSci Adv
January 2025
Medical Research Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou 510080, China.
Intracranial optical imaging of glioblastoma (GBM) is challenging due to the scarcity of effective probes with blood-brain barrier (BBB) permeability and sufficient imaging depth. Herein, we describe a rational strategy for designing optical probes crossing the BBB based on an electron donor-π-acceptor system to adjust the lipid/water partition coefficient and molecular weight of probes. The amphiphilic hemicyanine dye (namely, IVTPO), which exhibits remarkable optical properties and effective BBB permeability, is chosen as an efficient fluorescence/photoacoustic probe for in vivo real-time imaging of orthotopic GBM with high resolution through the intact skull.
View Article and Find Full Text PDFACS Sens
January 2025
Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Collaborative Innovation Centre of Henan Province for Green Manufacturing of Fine Chemicals, Henan Key Laboratory of Organic Functional Molecule and Drug Innovation, Henan International Joint Laboratory of Smart Molecules and Identification and Diagnostic Functions, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, P. R. China.
Hypochlorous acid can be employed as a biomarker for blood infection (such as sepsis) and tissue damage (such as drug-induced liver injury, DILI), and the diagnosis of tissue damage or blood infection can be achieved through the detection of hypochlorous acid in relevant biological samples. Considering the complex environment and the diverse interferences in living organisms and blood plasma, developing new detection methods for HClO with high signal-to-background ratios is particularly important, and it can improve the accuracy of detection and quality of imaging based on a higher contrast, which makes the detection of HClO clearer and more accurate. Here, based on the advantages of the NIR fluorescence/photoacoustic dual-modal probe, we reported a hypochlorous acid-activatable NIR fluorescence/photoacoustic dual-modal probe (NIRF-PA-HClO) based on the spirolactam ring-opening strategy in this paper.
View Article and Find Full Text PDFPhotoacoustics
February 2025
College of Engineering, Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
A novel balloon-type photoacoustic cell (BTPAC) is proposed to facilitate the detection limitations of acetylene (CH) gas achieving ppb level. Here, an ellipsoidal photoacoustic cavity is employed as the platform for gas-light interaction. By strategically directing the excitation source towards the focal point of the ellipsoidal cavity, ensuring its trajectory traverses the focal point upon each reflection from the interior walls.
View Article and Find Full Text PDFActa Pharm Sin B
December 2024
Guangdong Provincial Key Laboratory of New Drug Screening, NMPA Key Laboratory for Research and Evaluation of Drug Metabolism and Guangdong-Hong Kong-Macao Joint Laboratory for New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China.
Cervical cancer, the most common gynecological malignancy, significantly and adversely affects women's physical health and well-being. Traditional surgical interventions and chemotherapy, while potentially effective, often entail serious side effects that have led to an urgent need for novel therapeutic methods. Photothermal therapy (PTT) has emerged as a promising approach due to its ability to minimize damage to healthy tissue.
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