Functionalized Gold Nanoparticles for Visual Determination of Dopamine in Biological Fluids

Abstract

A facile, low-cost, and reliable visual method, based on 6-thioguanine (6-TG) functionalized gold nanoparticles (AuNPs), is introduced for highly sensitive and selective determination of dopamine. In this method, the hydrogen-bonding identification between 6-TG and dopamine can induce the collection of the functionalized AuNPs, causing the color of AuNPs to change from wine red to blue. Therefore, the presence of dopamine can be identified with bare eyes. Moreover, the concentration of dopamine can be quantitatively detected by a UV–vis spectrophotometer. Experiments reveal that in the range from 0.01 to 4 μM, the ratio of the peak at 650 and 520 nm (A 650/A 520) is linearly proportional to the dopamine concentration, with a lower limit of detection (LOD) of 4.6 nM (S/N = 3). In addition, the selective experiment reveals that the developed method shows high specificity. Meanwhile, this method can be used for the determination of trace levels of dopamine in practical samples, and it reveals a satisfied result. In conclusion, the proposed method is simple and convenient without any tedious treatment processes and sophisticated instruments. Furthermore, the designed method would provide a detection pathway for other organic interring species and make a valuable contribution to improve the visual method.

Modifier-free gold nanoparticle colorimetric sensing for detecting sulfanilamide in the presence of dopamine

“…The results obtained using the proposed method are not as sensitive and the calibration curve is not as wide as those of as other methods for DA determination. 21,51 However, this method can be considered when it is necessary to quickly analyze samples containing DA without any modification to AuNPs.…”

“…18 In addition to melamine, there have been many different works published on DA determination using either modified or unmodified AuNP solution, which were also based on the characteristic red-to-blue color change. [19][20][21][22] Previously, 5 nm AuNPs were used by J. Di et al for DA detection, and Cu 2+ ions were used to accelerate the aggregation.…”

“…17 DA was analyzed in other works from Y. Leng et al and C. Lai et al in a similar way, except that thioglycolic acid and 6-thioguanine played a role as a support for agglomeration. 19,21 Moreover, in recent studies, the combination of DA and AuNPs has achieved great and stunning results in other applications. Spherical or star-shaped AuNPs modified with polydopamine have been widely used in biomedicine, as especially drug carriers based on antitumor and antiangiogenic properties.…”

Multicolor colorimetric detection of dopamine based on iodide-responsive copper–gold nanoparticles

“…25,26 In typical schemes for the detection of DA using gold nanoparticles (Au NPs) or silver nanoparticles (Ag NPs), the hydrogen bonding between DA and other auxiliary molecules is mostly utilized. [27][28][29][30][31][32] However, specific modifications of Au/Ag nanoparticles are required. Recently, Yang et al prepared copper-gold nanoparticles (Cu-Au NPs) in the form of a chainlike aggregated state by replacing some chloroauric acid with copper sulfate.…”