Ag-containing metal organic framework reacted with AsH 3 : Mechanism and application for inorganic arsenic detection by hydride generation-smartphone RGB readout colorimetric system.

The reaction mechanism of Ag-containing metal organic framework (Ag-BTC) and hydrogen arsenide (AsH) was discussed in detail in this work. Silver ions in Ag-BTC were reacted with AsH, and silver nanoparticles were generated on the surface of Ag-BTC, causing its color changed. This property was further applied to a hydride generation-colorimetric analytical system. As(III) was converted to AsHvia hydride generation and then reacted with the Ag-BTC (immobilized on test paper), leading to the test paper changed from white to black. Visual colorimetric and smartphone RGB readout mode were used for this analytical system. The results could be readout by naked-eye in visual colorimetric mode and a smartphone in RGB readout mode. Under the optimized conditions, As(III) concentration as low as 10 μg/L and 50 μg/L could be readout by smartphone and naked-eye, respectively. This method was further successful applied to As(III) determination in real samples (drinking water samples and scented tea samples), with recoveries of 91-113%.