title: Sensitive colorimetric detection of K(I) using catalytically active gold nanoparticles triggered signal amplification.
abstract: In this work, we report a simple, ultrasensitive, and feasible colorimetric assay for metal ion (K(+), used as a model) via inherent peroxidase-like enzymatic amplification strategy of gold nanoparticles (AuNPs). It is shown that peroxidase-like activity of AuNPs can be improved dramatically by its surface activation with target-specific aptamer molecules. Whereas when the target exists, the aptamers leave the surface of AuNPs in a target concentration-dependent manner, resulting in a decrease of the nanoenzymatic catalytic ability of AuNPs. Thus, K(+) can be quantified in the presence of AuNPs by using a colorimetric sensing probe (3,3',5,5'-tetramethylbenzidine). The color change of the solution is relevant to the dose of the target, and this can be achieved with the naked eyes and monitored by UV-vis spectrometry. A linear dependence between the absorbance and target K(+) concentration is obtained under optimal conditions in the range from 0. 1 nM to 1 μM with a detection limit (LOD) of 0.06 nM estimated at the 3Sblank level. The sensitivity displays to be 2-9 orders of magnitude better than those of other K(+) detection methods. This sensing strategy may in principle be universally applicable for the detection of a range of environmental or biomedical molecules of interest.
authors.affiliation: Department of Chemistry, Capital Normal University, Beijing, 100048, China. Electronic address: czb979216@sina.com.
authors.forename: Zhengbo
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Department of Chemistry, Capital Normal University, Beijing, 100048, China; College of Resources Environment and Tourism, Capital Normal University, Beijing, 100048, China.
authors.forename: Lulu
authors.initials: L
authors.lastname: Tan
authors.affiliation: Department of Chemistry, Capital Normal University, Beijing, 100048, China.
authors.forename: Shaoxiong
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Chemistry, Capital Normal University, Beijing, 100048, China.
authors.forename: Yimeng
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Hematology, Chinese PLA General Hospital, Beijing, 100853, China. Electronic address: yonghuililab@163.com.
authors.forename: Yonghui
authors.initials: Y
authors.lastname: Li
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D001560:Benzidines / Q000737:chemistry; D015374:Biosensing Techniques / Q000379:methods; D002414:Cations, Monovalent / Q000032:analysis; D003124:Colorimetry / Q000379:methods*; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D011188:Potassium / Q000032:analysis*
chemical_list: D052157:Aptamers, Nucleotide; D001560:Benzidines; D002414:Cations, Monovalent; C021758:3,3',5,5'-tetramethylbenzidine; D006046:Gold; D011188:Potassium
keywords: Apatmer; Colorimetric; Gold nanoparticles; Potassium ion