Paper
1 March 1992 LED-compatible fluorosensor for ammonium ion and its application to biosensing
Otto S. Wolfbeis, Hong Li
Author Affiliations +
Abstract
We present a fluorescence-based sensing scheme for ammonium ion using nonactin as the receptor/carrier. The ammonium-sensitive material consists of a pvc membrane containing the nonactin, a plasticizer, and a proton carrier (lipophilic nile blue). Sensing is based on the selective extraction of the ammonium ions into the pvc membrane, and a concomitant release of a proton from the dye, contained in the pvc membrane, into the sample solution. Upon deprotonation, the dye undergoes a color change from blue to red which is detected via fluorescence intensity measurements. The sensor fully reversibly responds to ammonium ion, with detection limits varying from 0.03 to 10 mM at near neutral pH. Response times are about 1 min for membrane thicknesses of ca. 2 micrometers . The sensor is fully compatible with solid-state electronics (i.e., LED light sources and photodiode detectors) but suffers from a strong pH dependence of the signal so that the pH of the sample must be kept constant. The sensor is of potential utility in monitoring ammonium ion in wastewater and surface water samples, but may also act as a transducer in all kinds of biochemical reactions during which ammonium ion is released or consumed. Examples of biosensors for urea and creatinine are given.
© (1992) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Otto S. Wolfbeis and Hong Li "LED-compatible fluorosensor for ammonium ion and its application to biosensing", Proc. SPIE 1587, Chemical, Biochemical, and Environmental Fiber Sensors III, (1 March 1992); https://doi.org/10.1117/12.56532
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Cited by 4 scholarly publications.
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KEYWORDS
Ions

Sensors

Potassium

Urea

Luminescence

Fiber optics sensors

Environmental sensing

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