RESUMO
A simple and rapid electrochemical sensing method with high sensitivity and specificity of aptamers was developed for the detection of methylamphetamine (MAMP). A short anti-MAMP thiolated aptamer (Apt) with a methylene blue (MB) probe at 3'-end was immobilized on the surface of a gold electrode (MB-Apt-S/GE). The electrochemical signal appeared when MAMP presenting in the sample solution competed with cDNA for binding with MB-Apt-S. Under optimized conditions, the liner range of this signal-on electrochemical aptasensor for the detection of MAMP achieved from 1.0 to 10.0 nmol/L and 10.0-400 nmol/L. LOD 0.88 nmol/L were obtained. Satisfactory spiked recoveries of saliva and urine were also obtained. In this method, only 5 min were needed to incubate before the square wave voltammetry (SWV) analysis, which was much more rapid than other electrochemical sensors, leading to a bright and broad prospect for the detection of MAMP in biological sample. This method can be used for on-site rapid detection on special occasions, such as drug driving scenes, entertainment venues suspected of drug use, etc.
Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Técnicas Eletroquímicas , Metanfetamina , Técnicas Eletroquímicas/métodos , Técnicas Biossensoriais/métodos , Aptâmeros de Nucleotídeos/química , Humanos , Metanfetamina/urina , Metanfetamina/análise , DNA Complementar/genética , Saliva/química , Saliva/metabolismo , Eletrodos , Limite de Detecção , Ouro/química , Azul de Metileno/químicaRESUMO
Trace amounts of Co3O4 modified TiO2 nanorod arrays were successfully fabricated through the photochemical deposition method without adding any nocuous reagents. The Co3O4/TiO2 nanorod arrays fabricated in acid solution had the highest photo-electrochemical activity. We elaborated on the mechanism of Co3O4-TiO2 fabricated in different pH value solutions. The Co3O4-TiO2 had a more remarkable photo-electrochemical performance than the pure TiO2 nanorod arrays owing to the heterojunction between Co3O4 and TiO2. The degradation of methylene blue and hydroquinone was selected as the model reactions to evaluate the photo-electrochemical performance of Co3O4-TiO2 nanorod arrays. The Co3O4/TiO2 nanorod arrays had great potential in waste water treatment.