Water-soluble Au nanocages for enzyme-free H₂O₂sensor and 4-nitrophenol reduction

Nanocontainer in der Analytik

“…Diese kçnnen aus verschiedensten Materialien hergestellt werden, z. [26,27] Übersichtsartikel über Nanocontainer füra nalytische Anwendungen in den letzten fünf Jahren waren entweder auf ein bestimmtes Material spezialisiert [1,28] oder behandelten beispielsweise nur Anwendungen in der Biomedizin oder für Nanoreaktoren, wobei eine Sicht auf die Analytik entweder komplett fehlte oder auf ein Minimum beschränkt war. [11] All diese Strukturen haben eine große Oberfläche und ein großes inneres Volumen, das sie zum Einschluss von Molekülen befähigt und verschiedenste Oberflächenfunktionalisierungen ermçglicht.…”

Nanostructured Inorganic Materials at Work in Electrochemical Sensing and Biofuel Cells

“…A typical synthesis of Au nanocages involves 2.5 mL of the aqueous solution of HAuCl 4 (175 µM) to be added to 5 mL AgNCs solution using a syringe pump at a rate of 250 µL·min −1 under magnetic stirring and the final product is centrifuged and then dispersed in water for utilization. Figure 11a depicts the energy dispersion spectroscopy (EDS) mapping profile of Au nanocages, indicating the presence of the remaining Ag since the reaction conditions were manipulated to yield an Ag/Au atomic ratio of 33/67 for a better synergic effect between the silver and gold [139]. Typical CV profiles in 0.1 M PBS (pH = 7.2) are displayed within Figure 11b, and the reduction current changes gradually with the initial H 2 O 2 amount (Figure 11c).…”

“…Very recently, Li and coworkers introduced an enzyme-free H 2 O 2 sensor based on quasi-spherical Au nanocages prepared via a galvanic replacement reaction with HAuCl 4 in water at room temperature, where mono-dispersed quasi-spherical Ag nanocrystals (AgNCs) are used as sacrificial templates [139]. The principle of the galvanic replacement reactions in aqueous solution is driven by the difference in the electrochemical potential between two metals, herein Ag + /Ag (0.80 V vs. SHE) and AuCl 4 − /Au (1.00 V vs. SHE).…”

“…In general, all metals M for which E° < 1.00 V vs. SHE can be used as the sacrificial template to synthesize various shapes of AuM bimetallic NCs (the method has been optimized for various systems by Xia's group over the last decade [94,[140][141][142][143][144][145][146]). AgNCs are routinely synthesized via a one-pot synthesis such as polyol before a galvanic replacement reaction between the as-prepared sacrificial template and an aqueous HAuCl4 solution leading to hollow, porous AuNCs and Au nanocages [139,147]. A typical synthesis of Au nanocages involves 2.5 mL of the aqueous solution of HAuCl4 (175 μM) to be added to 5 mL AgNCs solution using a syringe pump at a rate of 250 μL•min −1 under magnetic stirring …”

“…AgNCs are routinely synthesized via a one-pot synthesis such as polyol before a galvanic replacement reaction between the as-prepared sacrificial template and an aqueous HAuCl 4 solution leading to hollow, porous AuNCs and Au nanocages [139,147]. A typical synthesis of Au nanocages involves 2.5 mL of the aqueous solution of HAuCl 4 (175 µM) to be added to 5 mL AgNCs solution using a syringe pump at a rate of 250 µL·min −1 under magnetic stirring and the final product is centrifuged and then dispersed in water for utilization.…”