Study On The Assembly Of Photoelectrochemical Functional Coupling Interface Mediated By Ru[bpy]₃²⁺ And DNA Sensing Detection

Photoelectrochemical coupling sensor is an important development direction of photoelectrochemical detection technology.The assembly of the functional coupling interface is essential for preparing the photoelectrochemical coupling sensor.Unlike a single functional interface,the bi-functional interface needs more functional coupling steps with a more variable and complicated coupling process,which increases the interface assembly blindness.Establishing a characterization method for the photochemical response properties of the coupling interface is beneficial to fully grasp the functional properties of the photochemical coupling.It significantly improves the coupling directivity to obtain an ideal coupling interface.To achieve the above goal,an SECM imaging method for interfacial photochemical bifunctional coupling distribution uniformity was established by synthesizing Ru[bpy]₃²⁺/Au NPs/Au composite.The proposed method was applied to characterize the coupling interface distribution uniformity of two composites,Ru[bpy]₃²⁺@Cu-MOF（-SH）/Au and Ru（dcbpy）₃²⁺-AMT/Au.In addition,two types of photoelectrochemical coupled DNA sensors were constructed based on the Ru（dcbpy）₃²⁺-AMT/Au interface.（1）By assembling the Ru[bpy]₃²⁺/Au NPs/Au interface,an in-situ analytical method was explored and established for the response properties of the photoelectrochemical coupled function.（1）Aiming at the interface strength response,an in-situ measurement method of signal response was established using a photoelectrochemical combination method of signal recording.（2）Aiming at the interfacial coupling distribution uniformity,an SECM imaging assessment method was developed by constructing the logical correlation between the imaging morphology and the coupled distribution uniformity within the range of coupled micro-region.Based on the principle of Ru[bpy]₃²⁺-Fc ECL quenching and MB REDOX reactions,the photoelectrochemical response of the assembled interface was validated.The results show that the solution-free Fc and MB response detection limits are 3.1 p M and 28.6 n M with linear ranges of 10.0 p M～100.0 n M and 100.0n M～100.0μM,respectively.The DNA sensing response effectiveness was verified for the assembled interface based on the complementary hybridization principle of DNA-AP to DNA-SP.The results show that the detection limits of both the ECL and EC response to SP is 0.3 f M and 5.6 p M with linear ranges of 400.0 p M～4.0μM and 10.0 p M～100.0 n M,respectively.The research results validate the effectiveness of photoelectrochemical functional coupling and DNA sensing response.（2）To develop a new interface coupling method of Ru[bpy]₃²⁺,the coupling interface of Ru（dcbpy）₃²⁺-AMT/Au was assembled using the dehydration condensation mercaptoylation between Ru（dcbpy）₃²⁺and AMT.The interfacial photoelectrochemical response properties were characterized using the established method.The results of signal response show that the detection limits of Fc and MB are 0.3 n M and 2.8 n M with linear ranges of 1.0 p M～10.0 n M and 10.0 n M～30.0μM,respectively.The imaging response results show that the interface-coupled uniformity performs well with a narrow signal response value range of 158.0～176.0and uniform color distribution.The DNA sensing response effectiveness results show that the detection limits of both the ECL and EC response to SP are 7.7 f M and 0.3n M with linear ranges of 100.0 f M～1.0 n M and 1.0 p M～10.0 n M,respectively.The research results validate the effectiveness of photoelectrochemical functional coupling and DNA sensing response.The assembled interface is available for constructing the photoelectrochemical function-coupling sensors with good photoelectrochemical response performance,coupled uniformity,and stability.（3）To explore a new way of interface-coupling,a Ru[bpy]₃²⁺@Cu-MOF（-SH）/Au coupling interface was assembled using a MOF-mediation strategy.The interfacial photoelectrochemical response properties were characterized using the established method.The results of signal response show that the detection limits of Fc and MB are 30.0 f M and 330.0 n M with linear ranges of 0.1 p M～1.0 n M and10.0μM～1.0 m M,respectively.The imaging response results show mediocre interface-coupled uniformity,with a slightly extensive signal response value range of147.0～171.0 and heterogeneous color distribution.The DNA sensing response effectiveness results show that the detection limits of both the ECL and EC response to SP is 0.3 n M and 35.6 n M with linear ranges of 1.0 n M～10.0 m M and 100.0 n M～1.0 m M,respectively.As a general coupling media mode,MOF-mediation provides a feasible interfacial photoelectrochemical function coupling scheme.（4）By using the DNA probe inversion hybridization strategy,an HBV gene sequence photoelectrochemical coupling sensor was fabricated based on the interface of Ru（dcbpy）₃²⁺-AMT/Au.The inverted three-stage hybridization of the target sequence can effectively drive the migration of solution-free SP from the interface delocalization to the near-domain,thus inducing an excellent photoelectrochemical dual-signal response.Under the optimized conditions,the ECL and EC response detection limits of the proposed sensor for the target sequence are 2.8 and 19.7 f M with linear ranges of 1.0 f M～10.0 p M and 100.0 f M～1.0 n M,respectively.The response balance times are～640 and～600 s.When used for detecting serum samples,ΔECL in ECL response change and SE%in EC response change is confirmed to be342.7 and 1480 for the sensor.The two parameters of photoelectrochemistry have the advantages of complementary functions,which can help to realize the rapid,accurate,and highly sensitive detection of HBV gene sequence in complicated biological matrix samples.（5）By using the strategy of lengthening the aptamer probe terminal extension complementary active pocket,a KAN photoelectrochemical coupling sensor was fabricated based on the interface of Ru（dcbpy）₃²⁺-AMT/Au.The active pocket recognition and electrostatic action of target KAN can effectively drive the migration of solution-free SP from the interface delocalization to the near-domain,thus inducing an excellent photoelectrochemical dual-signal response.Under the optimized conditions,the proposed sensor’s ECL and EC response detection limits for KAN are 32.5 and 314.0 p M with linear ranges of 100.0 p M～1.0μM and 1.0n M～10.0μM,respectively.The response balance times are～433 and～250 s.The two parameters of photoelectrochemistry are functionally adjustable.Different types of sensors with single-ECL,single-EC,and ECL-EC responses can be fabricated by controlling the probe labeling mode of the photoelectrochemical signaling indicators.The two parameters of photoelectrochemistry have the advantages of complementary functions,which can help to realize the rapid,accurate,and highly sensitive detection of KAN in practical samples.