A holographic fingerprint sensor has been developed for a system that identifies a person by his or her fingerprints. The sensor uses a laser as its light source and consists of a light-conducting plate, which is a transparent glass plate with a plain grating-type hologram, and a focusing lens system just under the hologram. Since the sensor uses a plane-parallel plate, all the optical paths from each point of a fingerprint to the hologram are equal, and a bright fingerprint can be created without the trapezoidal distortion that is inherent in conventional prism-type sensors.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1364/AO.31.001794 | DOI Listing |
Anal Chem
January 2025
Research Center for Analytical Sciences, Department of Chemistry, College of Sciences, Northeastern University, Box 332, Shenyang 110819, China.
The advancement of lanthanide fingerprint sensors characterized by targeted emission responses and low self-fluorescence interference for the detection of biothiols is of considerable importance for the early diagnosis and treatment of cancer. Herein, the lanthanide "personality function tailoring" HOF composite sensor array is designed for the specific discrimination of biothiols (GSH, Cys, and Hcy) based on the activation of various luminescent molecules, such as r-AuNCs/luminol via HOF surface proximity. Lumi-HOF@Ce serves as a versatile platform for catalyzing the oxidation of -phenylenediamine (OPD) to generate yellow fluorescent oligomers, accompanied by the fluorescence attenuation of luminol.
View Article and Find Full Text PDFJ Fluoresc
January 2025
Chongqing Engineering and Technology Research Center of Intelligent Rehabilitation and Eldercare, Chongqing City Management College, 401331, Chongqing, China.
The presence of excessive residues of pesticides poses a great threat to ecology and human health. Herein, a novel, low-cost, simple and precise quantification sensing platform was established for differentiating and monitoring four common pesticides in China. Particularly, the array-based ratio fluorescent sensor array detector (ARF-SAD) based on cross-reaction characteristics of porphyrins and other porphyrin derivative was successfully constructed and integrated into the platform.
View Article and Find Full Text PDFACS Sens
January 2025
Institute of Analytical and Bioanalytical Chemistry, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany.
Gastric cancer remains a leading cause of cancer-related mortality, requiring the urgent development of innovative diagnostic tools for early detection. This study presents an integrated infrared spectroscopic electronic nose system, a novel device that combines infrared (IR) spectroscopy and electronic nose (eNose) concepts for analyzing volatile organic compounds (VOCs) in exhaled breath. This system was calibrated using relevant gas mixtures and then tested during a feasibility study involving 26 gastric cancer patients and 32 healthy controls using chemometric analyses to distinguish between exhaled breath profiles.
View Article and Find Full Text PDFSensors (Basel)
December 2024
Computer Engineering Department, Engineering Faculty, Adnan Menderes University, 09100 Aydın, Türkiye.
Wireless Fidelity (Wi-Fi) based positioning has gained popularity for accurate indoor robot positioning in indoor navigation. In daily life, it is a low-cost solution because Wi-Fi infrastructure is already installed in many indoor areas. In addition, unlike the Global Navigation Satellite System (GNSS), Wi-Fi is more suitable for use indoors because signal blocking, attenuation, and reflection restrictions create a unique pattern in places with many Wi-Fi transmitters, and more precise positioning can be performed than GNSS.
View Article and Find Full Text PDFSensors (Basel)
December 2024
School of Biomedical Engineering, Sun Yat-sen University, Guangzhou 510275, China.
Security is one of the increasingly significant issues given advancements in technology that harness data from multiple devices such as the internet of medical devices. While protecting data from unauthorized user access, several techniques are used including fingerprints, passwords, and others. One of the techniques that has attracted much attention is the use of human features, which has proven to be most effective because of the difficulties in impersonating human-related features.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!