Hollow porous molecularly imprinted polymers as emerging adsorbents

Hollow porous molecularly imprinted polymers (HPMIPs) are identified as promising adsorbents with many advantageous properties (e.g., large number of imprinted cavities, highly accessible binding sites, controllable pore structure, and fast mass transfer). Because of such properties, HPMIPs can exhibit improved binding capacity and kinetics to make analyte molecules readily interact with a greater number of recognition sites on the imprinted shell. This review highlights the synthesis and utility of HPMIPs as adsorbents to cover diverse targets of interest (e.g., endocrine disrupting chemicals, pharmaceuticals, pesticides, and heavy metal ions). The overall potential of HPMIPs is thus discussed in the context of analytical chemistry with particular focus on the efficient extraction of trace-level targets from complex matrices.

Macro-/meso-porous NiCo2O4 synthesized by template-free solution combustion to enhance the performance of a nonenzymatic amperometric glucose sensor

A sensitive nonenzymatic amperometric glucose sensor is described that relies on a glassy carbon electrode modified with a macro-/meso-porous NiCo₂O₄. NiCo₂O₄ with spinel structure has been prepared via a one-step solution combustion method. The material was characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and nitrogen absorption/desorption. An electrode was coated with the porous material and then displayed excellent electrocatalytic activity towards the direct oxidation of glucose in 0.15 M NaOH solution by cyclic voltammetry. Amperometric I-t curve demonstrated a sensitivity of 2100 μA·mM^-1·cm^-2 at an applied potential of 0.45 V (vs Hg/HgCl). The sensor has a linear response in the 0.001 to 1.0 mΜ glucose concentration range, a fast response time (3.9 s) and a low detection limit (0.38 μΜ). Graphical abstract.