Selectively colorimetric detection of cysteine with triangular silver nanoprisms

Triangular silver nanoprisms were prepared and applied to make colorimetric detection of cysteine based on our findings that cysteine could lead to the blue shift of the dipole plasmon resonance absorption, but other 19 kinds of natural amino acids could not. Cysteine with a concentration 160 nmol/L can result in a color change that can be discerned with naked eyes.

Plasmonic locator with sub-diffraction-limited resolution for continuously accurate positioning

Both the accurate distance measurement and positioning information at the nanoscale are important for the analysis of micro/nano interactions.Plasmon ruler has been an indispensable optical tool to detect the chemical and biological dynamic processes via distance-dependent plasmon coupling in the nearly aggregated state.But it cannot disclose the detailed and accurate information of positions and dynamic movements of its two plasmonic components owing to the inherent diffraction limit.Herein,a plasmonic locator is presented which consists of a heterotypic pair of red/blue plasmonic components with significant wavelength difference(∼150 nm).Attributed to the detuned energy(∼0.64 eV)of the two components,the plasmonic locator has the ability of sub-diffraction-limited resolution(center to center,30 nm)and accurate positioning under conventional dark-field microscopy,making the relative dynamic information of nearby red/blue components be recorded accurately at video rate.As an important complement to the current aggregate science and technology of plasmonics,this newly developed plasmonic locator presents a facile means to realize super-resolution imaging,accurate positioning,and continuous tracing in chemical and biological interactions at the single-molecule level.

One-step synthesis of Cu(Ⅱ) metal–organic gel as recyclable material for rapid, efficient and size selective cationic dyes adsorption

Efficient removal of non-biodegradable and hazardous dyes from wastewater remains a hot research topic.Herein,a rationally designed a Cu(Ⅱ)-based metal–organic gel(Cu-MOG)with a nanoporous 3 D network structure prepared via a simple one-step mixing method was successfully employed for the removal of cationic dyes.The Cu-MOG exhibited high efficiency,with an adsorption capacity of up to 650.32 mg/g,and rapid adsorption efficiency,with the ability to adsorb 80%of Neutral Red within 1 min.The high adsorption efficiency was attributed to its large specific surface area,which enabled it to massively bind cationic dyes through electrostatic interaction,and a nanoporous structure that promoted intra-pore diffusion.Remarkably,the Cu-MOG displayed size-selective adsorption,based on adsorption studies concerning dyes of different sizes as calculated by density functional theory.Additionally,the adsorption performance of the Cu-MOG still maintained removal efficiency of 100%after three regeneration cycles.These results suggested that the Cu-MOG could be expected to be a promising and competitive candidate to conveniently process wastewater.