A novel hybrid sensor for combined imaging of dissolved oxygen and labile phosphorus flux in sediment and water.
A novel sensor assembled by a hybrid film was developed for 2D combined measurements of DO dynamic and labile P flux in sediment and water at sub-millimeter resolution based on PO and DGT techniques. The hybrid film is comprised of a transparent polyester membrane supporting two ultrathin sensing layers, i.e., a P binding layer (PBL) overlying a DO sensing layer (DSL). A robust, straightforward measuring strategy based on the referenced RGB and coloration-computer imaging densitometry (CID) methods was developed. Sensing properties for DO show a considerable homogeneity (RSD < 5%) and rapid response (<24 s) in fluorescent response. Calibration experiments reveal the sensitivity values for the DSL without/with PBL are 2.12/1.95, with an acceptable bias of less than 8%. The optimized PBL possesses a uniform distribution of zirconium-oxide microparticles at a relatively high DGT capacity (10.8 μg P cm-2), in which the distribution of adsorbed-P can be imaged by the coloration-CID method. The performance of the sensor is compared to two conventional PO and DGT sensors. The hybrid sensor was successfully deployed in three types of benthic micro-interface and showed significant small-scale heterogeneity, providing new opportunities for advancing investigations into relevant biogeochemical processes.
State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China. Electronic address: chan@niglas.ac.cn.
Chao
C
Han
Geological Survey of Jiangsu Province, Nanjing 210018, China.
Jinghua
J
Ren
State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
Zhaode
Z
Wang
State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
Hao
H
Tang
State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China. Electronic address: dxu@niglas.ac.cn.
Di
D
Xu
D019015:Geologic Sediments / Q000737:chemistry*; D060106:Lakes / Q000737:chemistry; D010100:Oxygen; D010758:Phosphorus / Q000737:chemistry*; D014867:Water; D014874:Water Pollutants, Chemical
D014874:Water Pollutants, Chemical; D014867:Water; D010758:Phosphorus; D010100:Oxygen
Combined imaging; DGT; DO; Hybrid sensor; Labile P flux; PO