title: A portable system for on-site quantification of formaldehyde in air based on G-quadruplex halves coupled with A smartphone reader.
abstract: A portable colorimetric determination system based on G-quadruplex DNAzyme integrated with a smartphone was developed to quantitatively detect formaldehyde (FA). The method is based on the oxidation of FA by H2O2, which prevents the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS)–H2O2 reaction catalyzed by G-quadruplex halves. With the addition of FA, the amount of the blue-green-colored free-radical cation (ABTS+) was reduced. The concentration of FA can be determined by monitoring this competitive reaction with a UV-vis spectrometer. Response surface methodology (RSM) and Box-Behnken design (BBD) were applied for optimization of the colorimetric assay. A smartphone-based colorimetric reader was also developed, which could display FA responses and report the concentration in real-time. The system could detect FA as low as 0.01 µM with a linear range of 1-600 µM. Taking advantages of smartphone and DNAzyme, the assay provides great potential for its practical application as a home testing or on-site analysis with high sensitivity and selectivity.
authors: Xin
authors: X
authors: Yang
authors: Yanru
authors: Y
authors: Wang
authors: Wei
authors: W
authors: Liu
authors: Yuhuan
authors: Y
authors: Zhang
authors: Fangqing
authors: F
authors: Zheng
authors: Shuaixing
authors: S
authors: Wang
authors: Daohong
authors: D
authors: Zhang
authors: Jianlong
authors: J
authors: Wang
mesh_terms: D000388:Air / Q000032:analysis*; D052160:Benzothiazoles / Q000737:chemistry; D015374:Biosensing Techniques; D003124:Colorimetry; D021881:DNA, Catalytic / Q000737:chemistry; D005557:Formaldehyde / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification*; D054856:G-Quadruplexes; D006861:Hydrogen Peroxide / Q000737:chemistry; D000068997:Smartphone; D013451:Sulfonic Acids / Q000737:chemistry
chemical_list: D052160:Benzothiazoles; D021881:DNA, Catalytic; D013451:Sulfonic Acids; D005557:Formaldehyde; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; D006861:Hydrogen Peroxide