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Title: Smart-phone, paper-based fluorescent sensor for ultra-low inorganic phosphate detection in environmental samples
Abstract

A major goal of environmental agencies today is to conduct point-of-collection monitoring of excess inorganic phosphate (Pi) in environmental water samples for tracking aquatic “dead zones” caused by algae blooms. However, there are no existing commercial devices which have been miniaturized and are suitable for the point-of-need-testing (“PONT”) that is required to fully map a large region, such as the Florida Everglades. To solve this challenge, a reflection-mode fluorescence-sensing apparatus was developed, leveraging an environmentally sensitive fluorophore (MDCC) bound to a bacterial phosphate-binding protein to generate a fluorescent optical signal proportional to the concentration of (Pi) present. The combined end-to-end integrated sensor system had a response time of only 4 s, with minimal effects of common interfering agents and a linear range spanning from 1.1 to 64 ppb. To support ease-of-use during PONT, the platform incorporated disposable wax-printed paper strip sample pads and a smartphone camera detection system. Since the EPA threshold is currently 30 ppb to prevent eutrophication, this system serves as a rapid test of whether a region is compliant.

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Award ID(s):
1647837
NSF-PAR ID:
10154333
Author(s) / Creator(s):
; ; ;
Publisher / Repository:
Nature Publishing Group
Date Published:
Journal Name:
Microsystems & Nanoengineering
Volume:
5
Issue:
1
ISSN:
2055-7434
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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