9,10-Diphenylanthracene
cubic nanoparticles (DPA CNPs) with aggregation-induced emission characteristic
(AIEgens) were synthesized through a facile reprecipitation method;
then, a bright and stable electrochemiluminescence (ECL) signal can
be observed when the DPA CNPs were modified at the glassy carbon electrode
(GCE) in the presence of Tri-n-propylamine (TPA).
This phenomenon is ascribed to the molecules with restricted movement
that greatly blocked the energy leakage during the relaxation of the
excited state, which facilitated the emission of energy in the form
of photons. In addition, the size confinement effect of DPA CNPs in
the aggregated state effectively enhanced the ECL emission. The application
of DPA CNPs with AIE characteristics in an electrochemiluminescence
immunosensor has not been reported. In this contribution, a free-label
aggregation-induced electrochemiluminescence immunosensor based on
DPA CNPs was fabricated and a simple strategy for ultrasensitive detection
of aflatoxin B1 (AFB1) was proposed. The ECL
signal is quenched linearly in the range of 0.01 pg/mL to 100 ng/mL
for AFB1, and the detection limit is 3 fg/mL. In summary,
the prepared sensor exhibits high sensitivity, acceptable accuracy,
good anti-interference ability and stability, and satisfactory detection
toward AFB1 in walnut samples. Therefore, the fabricated
immunosensor will have significant applications in the fields of food,
medicine, and so on.