Chemical sensors based on periodic mesoporous organosilica @NaYF4:Ln3+ nanocomposites

Abstract

Here, three unique organic–inorganic hybrid nanocomposite materials prepared by combining NaYF₄:Yb³⁺,Ln³⁺ (Ln³⁺ = Er³⁺, Tm³⁺, Ho³⁺) and periodic mesoporous organosilica (PMO) are proposed for both metal ion sensing and solvent sensing. The luminescence properties of the developed hybrid materials, PMO@NaYF₄:Yb³⁺,Ln³⁺, were studied in detail in the solid state and after dispersing in water. It is found that PMO@NaYF₄:Yb³⁺,Er³⁺ showed selective “turn on” luminescence for Hg²⁺ with the detection limit of 24.4 μM in an aqueous solution. Additionally, the above three materials showed different luminescence emission responses towards water and organic solvents. It is worth noting that all three PMO@NaYF₄:Yb³⁺,Ln³⁺ materials showed “turn on” luminescence towards alcohols. PMO@NaYF₄:Yb³⁺,Er³⁺ and PMO@NaYF₄:Yb³⁺,Ho³⁺ were selected and further developed into sensitive sensors for the detection of water in alcohols by taking advantage of their quenching behavior in water. The detection limit for sensing of water was determined to be 0.21%, 0.18% and 0.29%, corresponding to isopropanol (PMO@NaYF₄:Yb³⁺,Er³⁺), n-butanol (PMO@NaYF₄:Yb³⁺,Er³⁺) and ethanol (PMO@NaYF₄:Yb³⁺,Ho³⁺), respectively. The above results illustrate the potential of these hybrid materials for applications in environmental fields as well as in chemical industries.