Detection of adenosine triphosphate through polymerization-induced aggregation of actin-conjugated gold/silver nanorods

Autor: Chih-Ching Huang, Yu-Ju Liao, Huan-Tsung Chang, Chia-Lun Hsu, Yen-Chun Shiang, Li-Yi Chen
Rok vydání: 2013
Předmět:
Zdroj: Nanotechnology. 24(44)
ISSN: 1361-6528
Popis: We have developed a simple and selective nanosensor for the optical detection of adenosine triphosphate (ATP) using globular actin-conjugated gold/silver nanorods (G-actin?Au/Ag NRs). By simply mixing G-actin and Au/Ag NRs (length ?56?nm and diameter ?12?nm), G-actin?Au/Ag NRs were prepared which were stable in physiological solutions (25?mM Tris-HCl, 150?mM NaCl, 5.0?mM KCl, 3.0?mM MgCl2 and 1.0?mM CaCl2; pH?7.4). Introduction of ATP into the G-actin?Au/Ag NR solutions in the presence of excess G-actin induced the formation of filamentous actin-conjugated Au/Ag NR aggregates through ATP-induced polymerization of G-actin. When compared to G-actin-modified spherical Au nanoparticles having a size of 13?nm or 56?nm, G-actin?Au/Ag NRs provided better sensitivity for ATP, mainly because the longitudinal surface plasmon absorbance of the Au/Ag NR has a more sensitive response to aggregation. This G-actin?Au/Ag NR probe provided high sensitivity (limit of detection 25 nM) for ATP with remarkable selectivity (>10-fold) over other adenine nucleotides (adenosine, adenosine monophosphate and adenosine diphosphate) and nucleoside triphosphates (guanosine triphosphate, cytidine triphosphate and uridine triphosphate). It also allowed the determination of ATP concentrations in plasma samples without conducting tedious sample pretreatments; the only necessary step was simple dilution. Our experimental results are in good agreement with those obtained from a commercial luciferin?luciferase bioluminescence assay. Our simple, sensitive and selective approach appears to have a practical potential for the clinical diagnosis of diseases (e.g. cystic fibrosis) associated with changes in ATP concentrations.
Databáze: OpenAIRE