Self‐Template Synthesis of Mesoporous Metal Oxide Spheres with Metal‐Mediated Inner Architectures and Superior Sensing Performance

Abstract

AbstractThe development of a general strategy to synthesize mesoporous metal oxide spheres (MMOSs) with tailorable compositions and architectures is desirable and challenging. Herein, a general self‐template strategy is demonstrated for the synthesis of MMOSs with tunable compositions (i.e., ZnO, Al2O3, Co3O4, Fe2O3, CuO) and metal‐mediated inner architectures via thermal decomposition of metal‐phenolic coordination polymers (MPCPs). The metal species in MPCPs can obviously influence the decomposition temperature of the polymer networks (Td). The inner architectures of MMOSs are determined by Td and the crystallization temperature of metal oxides (Tc). The MMOSs show solid inner architectures when Td > Tc or Td < Tc and hollow structure when Td ≈ Tc. Encouraged by their high surface area and accessible mesopores, gas sensors based on MMOSs (i.e., ZnO) are fabricated, which shows a low working temperature (250 °C) for detection of ethanol gas. The MMOSs (i.e., Co3O4) can further be used to fabricate sensing platform for detecting DNA analogue of miRNA‐21 (a biomarker abnormally expressed in most of solid tumors). Such MMOSs show high sensitivity (0.19 × 10−9m) and can even efficiently distinguish the target DNA from single‐, double‐ and triple‐base mismatched DNA.