简介:A Nafion/multi-wall carbon nanotubes (MWNTs) composite film-modified electrode was fabricated and
applied for the sensitive and selective determination of caffeine. Multi-wall carbon nanotubes (MWNTs)
were easily dispe简介:A Nafion/multi-wall carbon nanotubes (MWNTs) composite film-modified electrode was fabricated and
applied for the sensitive and selective determination of caffeine. Multi-wall carbon nanotubes (MWNTs)
were easily dispersed homogeneously into methanol by ultrasonication in the presence of 0.1% Nafion.
After evaporating the methanol, a Nafion/MWNTs composite film-modified electrode was achieved. Caffeine
can be effectively accumulated at Nafion/MWNTs composite film-modified electrode and produce a
sensitive anodic peak at around 1330 mV (vs. SCE) in a 0.01 mol L1 H2SO4 medium (pH 2.0). Compared to
the bare electrode and Nafion film-modified electrode, the Nafion/MWNTs film-modified electrode can
remarkably increase the anodic peak current of caffeine. Under the suitable conditions, the anodic peak
current was linear to caffeine concentration in the range of 6.0 1074.0 104 mol L1, and the limit
of detection was 2.3 107 mol L1. The Nafion/MWNTs composite film-modified electrode can be
renewed by repetitiously cycling in a blank solution for about three cycles. This newly exploited method
was successfully used to determine caffeine in beverage samples.详细>