The authors also show that while ZIF-8 wrapped UAANs are suitable for trace detection of HCH, thanks to the presence of ZIF-8 microporosity, sensitivity decreases for higher concentrations, compared with bare UAANs (Figure -iii). This is ascribed to the same porosity being saturated as bulk concentration of HCH increases. The sieving properties of the platform were explored, by showing that a small molecule such as 4-aminothiophenol can in fact diffuse through the porous framework, while Rhodamine 6G cannot.