Core–shell “loading-type” nanomaterials enabling glucometer readout for portable and sensitive detection of p-aminophenol in real samples

A one-target-many-trigger signal model sensing strategy is proposed for quickly, sensitive and on-site detection of the environmental pollutant p-aminophenol (PAP) by use of a commercial personal glucose meter (PGM) for signal readout with the core–shell “loading-type” nanomaterial MSNs@MnO₂ as amplifiable nanoprobes. In this design, the mesoporous silica nanoparticles (MSNs) nanocontainer with entrapped signal molecule glucose is coated with redoxable manganese dioxide (MnO₂) nanosheets to form the amplifiable nanoprobes (Glu-MSNs@MnO₂). When encountered with PAP, the redox reaction between the MnO₂ and PAP can induce the degradation of the outer layer of MSNs@MnO₂, liberating multiple copies of the loaded glucose to light up the PGM signal. Owing to the high loading capability of nanocarriers, a “one-to-many” relationship exists between the target and the signal molecule glucose, which can generate adequate signal outputs to achieve the requirement of on-site determination of environmental pollutants. Taking advantage of this amplification mode, the developed PAP assay owns a dynamic linear range of 10.0–400 μM with a detection limit of 2.78 μM and provides good practical application performance with above 96.7 ± 4.83% recovery in environmental water and soil samples. Therefore, the PGM-based amplifiable sensor for PAP proposed can accommodate these requirements of environment monitoring and has promising potential for evaluating pollutants in real environmental samples. Graphical Abstract: (Figure presented.)