Abstract

Development of specific and sensitive electrochemical sensing platform for thrombin (TB) analysis is highly desirable for its important roles in many diseases. Herein, we designed and explored a facile ratiometric electrochemical aptasensor for TB detection based on signal on–off strategy. AuNPs-MXene was synthesized, characterized, and used to functionalize the basic electrode as a signal-amplified sensing platform. Hairpin probe (Hp) labeled with ferrocene (Fc) as signal probe, TB aptamer (TBA) labeled with methyl blue (MB) as capture probe are rationally introduced to fabricate highly-selective recognition and ratiometric dual-signal readout aptasensor. The sequence of Fc-Hp was designed to be complementary with MB-TBA to form a double-stranded DNA structure. When TB is present, the specific interaction between MB-TBA and TB leads to the departure of MB-TBA and the formation of hairpin structure of Fc-Hp, resulting in the leaving away of MB and confining Fc group near the electrode surface. Consequently, the oxidation peak current (Ipa) of Fc increased (signal-on), meanwhile Ipa of MB decreased (signal-off). Thus, the specific recognition of MB-TBA to TB can be read out in an electrochemical signal on–off ratiometric mode. A novel ratiometric electrochemical aptasensor was constructed with a wide linear range of 5.0 fmol/L ∼ 1.0 pmol/L and a low detection limit of 1.7 fmol/L (3S0/S). Moreover, this ratiometric electrochemical aptasensor shows excellent selectivity, outstanding sensitivity, and good stability in real serum sample analysis, exhibiting promising potential application in bioanalysis.

Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call