A smartphone-assisted portable biosensor using laccase-mineral hybrid microflowers for colorimetric determination of epinephrine.

A novel smartphone-assisted portable biosensor based on laccase-mineral hybrid microflowers (La-HMFs) was applied for real-time, accurate and reliable quantification of epinephrine (EP). La-HMFs with flower-like hierarchical nanostructure was synthesized via biomineralization using Cu3(PO4)2⋅3H2O as the mineral. Characterization results revealed laccase molecules as the framework were immobilized within La-HMFs. Smartphone-assisted colorimetric assays showed wide linear detection range (1-400 μM) and favorable anti-interference ability for EP detection, and the detection limit was 0.6 μM. Further, due to the protective effect of Cu3(PO4)2⋅3H2O, the immobilized laccase exhibited good stability and desirable reusability.