Paper-based scanometric assay for lead ion detection using DNAzyme.
A facile and simple paper-based scanometric assay was developed to detect Pb(2+) using GR5-DNAzyme. Magnetic beads (MBs) and gold nanoparticles (AuNPs) were used as a signal collector and a signal indicator, respectively. They were linked together by GR5-DNAzyme, comprising an enzyme and a substrate strand pairing up with each other. In the presence of Pb(2+), the substrate strand is cut into two pieces, resulting in the disassembly of AuNPs from the MBs. These AuNPs were spotted on predefined areas on a chromatography paper, where signal is amplified through silver reduction. This sensing platform exhibits high sensitivity and selectivity toward Pb(2+), giving a detection limit of 0.3 nM and a linear fitting range from 0.1 to 1000 nM. Testing of this biosensor in river water and synthetic urine samples also showed satisfying results. Besides offering simultaneous and multi-sample analysis, this paper-based sensing platform presented here could be potentially applied and served as a general platform for on-site, naked eyes, and low-cost monitoring of other heavy metal ions in environmental and body fluid samples.
School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bang Khun Thian Campus, Bangkok 10150, Thailand.
Pasara
P
Vijitvarasan
Biochemical Engineering and Pilot Plant Research and Development Unit, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency at King Mongkut's University of Technology Thonburi, Bang Khun Thian, Bangkok 10150, Thailand. Electronic address: sukunya.oae@biotec.or.th.
Sukunya
S
Oaew
School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bang Khun Thian Campus, Bangkok 10150, Thailand. Electronic address: werasak.sur@kmutt.ac.th.
Werasak
W
Surareungchai
D015374:Biosensing Techniques; D021881:DNA, Catalytic / Q000378:metabolism*; D006046:Gold / Q000737:chemistry / Q000378:metabolism; D007477:Ions / Q000032:analysis / Q000378:metabolism; D007854:Lead / Q000032:analysis* / Q000378:metabolism; D053768:Metal Nanoparticles / Q000737:chemistry; D010209:Paper
D021881:DNA, Catalytic; D007477:Ions; D007854:Lead; D006046:Gold
Colorimetric sensing; DNAzyme; Lead ion detection; Scanometric assay