The chemical formula of guanidine hydrochloride is CH₆ClN₃, which is a kind of white or yellowish lump organic substance. Used as an intermediate for medicines, pesticides, dyes and other organic compounds. It is an important raw material for the manufacture of sulfa drugs and folic acid. It can also be used as an antistatic agent for synthetic fibers. In addition, guanidine hydrochloride can also be used in the field of nanotechnology. Next, the editor will introduce the application of guanidine hydrochloride in gold nanoclusters to prepare guanidine hydrochloride/6-aza-2-thiothymine-gold nanoclusters method.

(1) Mix 6-aza-2-thiothymidine with a concentration of 80mmol/L containing 0.2mol/L sodium hydroxide and a chloroauric acid solution with a concentration of 10mg/mL in a 1:1 volume ratio. After magnetic stirring at room temperature, the 6-aza-2-thiothymine-gold nanocluster solution was obtained after dialysis with a dialysis bag with a molecular weight cut-off of 3500 in deionized water;

(2) Add a guanidine hydrochloride solution with a concentration of 40mmol/L to the 6-aza-2-thiothymine-gold nanocluster solution, and the mixed volume ratio is 1:9, and it is incubated in a water bath for 20 minutes, and the reaction temperature of the water bath is 37℃ to obtain guanidine hydrochloride/6-aza -2-thiothymine-gold nano Cluster solution.

(3) Guanidine hydrochloride/6-aza-2-thiothymine-gold nanocluster powder is obtained after freeze-drying the guanidine hydrochloride/ 6-aza-2-thiothymine- gold nanocluster solution;

The aqueous solution of guanidine hydrochloride/6-aza-2-thiothymine -gold nanoclusters is yellow-green, and produces strong green fluorescence under ultraviolet light. The ultraviolet-visible spectrum has characteristic absorption peaks at 405nm, 460nm and 495nm, and the fluorescence spectrum has excitation peaks at 407nm, 465nm and 495nm. The maximum emission peak is at 530 nm, and the fluorescence quantum yield is 71%.

The preparation method has the advantages of simplicity, environmental protection, etc. The prepared gold nanoclusters have the characteristics of strong green fluorescence, wide excitation spectrum, narrow emission spectrum, high stability, and high fluorescence quantum yield.

References

CN 105860963 A Guanidine hydrochloride/6-aza-2-thiothymine-gold nano cluster and preparation method thereof.