Computer-Readable DNAzyme Assay on Disc for ppb-Level Lead Detection

Abstract

A method for the convenient detection of lead at the parts-per-billion (ppb)-level has been developed; it uses a conventional compact disc (CD) as the platform for preparing DNAzyme assays and an unmodified optical drive of ordinary desktop/laptop computers as the readout device. In particular, by immobilization of Pb(2+)-specific DNAzyme sensing constructs on the "transparent side" of a conventional CD-R via mild surface reactions, the Pb(2+) concentration can be determined by a free diagnostic program that checks the error distribution on the CD (i.e., it extracts the number of errors in a prerecorded audio file). The reading errors increase monotonically over a wide range of Pb(2+) concentrations (from 10 nM to 1 mM), and the selectivity is confirmed by testing several other divalent cations (Zn(2+), Ba(2+), Mg(2+), Ca(2+), Cu(2+), and Hg(2+)).

Novel plastic biochips for colorimetric detection of biomolecules

“…For constructing this type of biochip, it is believed that the transduction of biorecognition events into visual signals is the critical step, which is typically realized by using enzyme- [17,18] or nanoparticle- [10][11][12][13][14][15][16][17][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33] catalyzed deposition strategies. Gold nanoparticle (AuNP) labeling followed by silver staining (also called autometallography or silver enhancement) is one of the most efficient ways to achieve color labeling and signal amplification, thus has been widely adopted in colorimetric detection in the past decade [10,11,14,16,20,[23][24][25][29][30][31]. For example, AuNP-labeled DNA and protein biochips have been developed for colorimetric detection of target DNA [10,11,18,30,32], bioactive proteins [12, 14-16, 20, 21, 23-25, 28-31], pesticides [13,17], small biomolecules …”

“…Gold nanoparticle (AuNP) labeling followed by silver staining (also called autometallography or silver enhancement) is one of the most efficient ways to achieve color labeling and signal amplification, thus has been widely adopted in colorimetric detection in the past decade [10,11,14,16,20,[23][24][25][29][30][31]. For example, AuNP-labeled DNA and protein biochips have been developed for colorimetric detection of target DNA [10,11,18,30,32], bioactive proteins [12, 14-16, 20, 21, 23-25, 28-31], pesticides [13,17], small biomolecules [15,21,29], and heavy metal ions [19,27,31]. However, it should be pointed out that the current colorimetric-based biochips are conventionally fabricated on a rigid glass or oxidized silicon substrates, and have the following limitations: high fabrication cost, complicated surface treatment, and easily broken nature [34,35].…”

DNAzyme-Functionalized Gold Nanoparticles for Biosensing

“…When Pb 2+ was present in samples, fewer AuNPs were decorated on the disc to induce error in disc reading. Any optical drive from a computer could be used as a reader for this Pb 2+ detection with the disc [265]. We also developed a method to use a low-cost commercial device, a glucose meter, to detect Pb 2+ using DNAzymes, although no AuNPs were involved in the method [286].…”

Iodide-induced adsorption of lead(II) ion on a glassy carbon electrode modified with ferroferric oxide nanoparticles

“…Among heavy metals, lead is considered a major environmental pollutant because of its toxic and accumulative biological effects [1,2]. Many health problems such as memory loss, irritability, anemia, and muscle paralysis arise from ingestion of lead, due to the use of gasoline antiknock products, paint pigments, fertilizers and pesticides [3][4][5]. Lead is also a potential neurotoxin that can be accumulated in and ultimately damage bones and kidneys.…”