A format for a disposable screen-printed biosensor was investigated for monitoring formaldehyde. The screen-printed sensor format comprised a working electrode (WE) modified with platinised carbon, a new lipophilic tetrathiafulvalene-tetracyanoquinodimethane (TTF-TCNQ) salt as mediator, a plasticised polyurethane membrane (TECOFLEX SG80, PU) with anionic sites and the enzyme (formaldehyde dehydrogenase FOH) and co-factor (beta-NAD(+)). The new lipophilic TTF-TCNQ salt gave a smooth, robust electrode surface rather than microcrystalline deposits of the salt observed with TTF-TCNQ salts. Entrapment of the enzyme and co-factor behind a plastcised PU membrane with anionic sites enhanced the sensitivity and stability of the sensor. A linear response between 10(-3) and 10(-4) mol dm(-3) was observed. To demonstrate the feasibility of the use of the screen-printed sensor to monitoring formaldehyde in ambient air, preliminary experiments were carried out in the vicinity of a local medium density fibreboard factory and its performance compared to that of a biosensor made from the same platinised carbon and enzyme system, but without the lipophilic TTF-TCNQ and membrane, using a commercial 'Rank' cell. Samples were collected using a Molspin 'Super-sniffer'.
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http://dx.doi.org/10.1016/s0039-9140(01)00567-7 | DOI Listing |
Environ Monit Assess
January 2025
Laboratory for Ecotoxicology and Environmental Forensics, University of Benin, PMB 1154, Benin City, Nigeria.
This research was carried out to assess the concentrations of carbon monoxide (CO) and formaldehyde (HCHO) in Edo State, Southern Nigeria, using remote sensing data. A secondary data collection method was used for the assessment, and the levels of CO and HCHO were extracted annually from Google Earth Engine using information from Sentinel-5-P satellite data (COPERNISCUS/S5P/NRTI/L3_) and processed using ArcMap, Google Earth Engine, and Microsoft Excel to determine the levels of CO and HCHO in the study area from 2018 to 2023. The geometry of the study location is highlighted, saved and run, and a raster imagery file of the study area is generated after the task has been completed with a 'projection and extent' in the Geographic Tagged Image File Format (.
View Article and Find Full Text PDFSci Total Environ
January 2025
Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea. Electronic address:
Formaldehyde (HCHO), a major carbonyl compound in urban air, poses health risks due to its carcinogenic properties. However, the role of FT-PBL exchange in HCHO and the importance of vertical exchange on diurnal variations in HCHO remain unclear. This study investigated the diurnal variability of HCHO in Seoul's planetary boundary layer (PBL) during cold.
View Article and Find Full Text PDFSci Data
December 2024
Department of Colorectal Surgery, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.
Differences in prognostic outcomes are prevalent in patients with colorectal cancer liver metastases. Comparative analysis of tissue samples, particularly applying single-cell transcriptome sequencing technology, can provide a deeper understanding of potential impacting factors. However, long-term monitoring for prognosis determination necessitates extended preservation of tissue samples using formalin-fixed and paraffin-embedded (FFPE) treatments, which can cause substantial RNA degradation, presenting challenges to single-cell or single-nucleus sequencing.
View Article and Find Full Text PDFEnviron Pollut
December 2024
College of Environment and Climate, Institute for Environmental and Climate Research, Jinan University, Guangzhou, 511443, China; Guangdong Provincial Observation and Research Station for Atmospheric Environment and Carbon Neutrality in Nanling Forests, Guangzhou, 511443, China; Australia-China Centre for Air Quality Science and Management (Guangdong), Guangzhou, 511443, China.
Formaldehyde (HCHO) is a key player in photochemical processes and serves as a crucial precursor in the formation of hydroxyl radicals and ozone (O). While satellite observations can offer extensive spatiotemporal distributions of HCHO at both global and regional scales, the reliability of these satellite-derived HCHO measurements remains uncertain. In this study, we generated a five-year (June 2018-May 2023) Level 3 HCHO dataset, by applying spatial averaging technique to the TROPOspheric Monitoring Instrument (TROPOMI) Level 2 data.
View Article and Find Full Text PDFSensors (Basel)
December 2024
Department of Environmental Engineering, Pukyong National University, Busan 48513, Republic of Korea.
Rapid industrialization and the influx of human resources have led to the establishment of industrial complexes near urban areas, exposing residents to various air pollutants. This has led to a decline in air quality, impacting neighboring residential areas adversely, which highlights the urgent need to monitor air pollution in these areas. Recent advancements in technology, such as Solar Occultation Flux (SOF) and Sky Differential Optical Absorption Spectroscopy (SkyDOAS) used as remote sensing techniques and mobile extraction Fourier Transform Infrared Spectrometry (MeFTIR) used as an in situ technique, now offer enhanced precision in estimating the pollutant emission flux and identifying primary sources.
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