Efficient Immobilization of Tyrosinase Enzyme on Layered Double Hydroxide Hybrid Nanomaterials for Electrochemical Detection of Polyphenols

Gold screen-printed electrodes coated with thin films of layered double hydroxides containing cobalt and aluminium (Co
_1.57
Al(OH)
_x
SO
₄
, shortened as CoAl) have been investigated for the design of an electrochemical tyrosinase-based biosensor used for the detection of a complex mixture of polyphenols extracted from green tea. Physicochemical analyses show that the resulted biosensor exhibits very attractive characteristics: a high sensitivity, a large dynamic range (up to 1000 ng.mL
^-1
), and very low limits of detection (0.33 pg.mL
^-1
and 0.03 pg.mL
^-1
for oxidation and reduction, respectively).