Optical and electrochemical responses of an anthrax biomarker based on single-walled carbon nanotubes covalently loaded with terbium complexes.

An effective single-walled carbon nanotube (SWNT) covalently loaded with unsaturated terbium emissive material was designed for specific and rapid (2-3 s) detection of calcium dipicolinate (CaDPA) (detection limit 1 μM). The nanoprobe was successfully assembled onto electrodes and its sensing abilities were investigated through electrochemical measurement. Cyclic voltammetry curves were selectively responsive to calcium dipicolinate compared with benzoic acid, o-phthalic acid and m-phthalic acid. This novel material provides dual opto-electrochemical recognition of the anthrax biomarker CaDPA.