The Application Of Novel Eletrochemical Sensor And Light-electricity Dual Signal Sensor In Detecting Serum Markers

Using ultrasensitive analytical methods based on nanomaterials could realize early identification and determination even at very low levels.Among these analytical methods,electrochemical detection and electrochemiluminescence（ECL）analysis have been widely applied to detect serum markers.Nanomaterial-based electronic signal and light signal amplifications have great potential of improving both sensitivity and stability for sensors.In our work,we used c-C₆₀/CeO₂/PtNPs nanocomposites as signal label to construct electrochemical sensor for the detection of serum CYP2C19*2 gene.Besides,to improve accuracy,we used sulfur-doped palladium nanoflowers（s-PdNFs）as signal label to construct electrochemiluminescence-electrochemical dual signal sensor（light-electricity dual signal sensor）for the detection of serum PCSK9protein.The prepared dual signal sensor could improve the accuracy of the detection and meet two instruments（electrochemical and electrochemiluminescence）.This study not only provided a novel detection method for clinically determining the dosage of clopidogrel,but also provided a new detection technique for the efficacy evaluation of the PCSK9 inhibitor.These strategies of relevant technology platform are generally applicable to the analysis of serum DNA and protein markers.1.An electrochemical sensor for the detection of CYP2C19*2 gene using c-C₆₀/CeO₂/PtNPs as a signal labelThe disposition dose of clopidogrel is different in CYP2C19*2 gene carriers and non-carriers.High-dose clopidogrel has been recommended to overcome the low-responsiveness to clopidogrel in patients with the CYP2C19*2 gene.To realize the personalized therapy,it is necessary to efficiently and accurately analyse the genetic phenotype of CYP2C19*2in patients.Thus,we developed an ultrasensitive electrochemical biosensor to detect serum free CYP2C19*2 gene.First,Au nanoparticles@Fe-MIL-88NH₂（AuNPs@Fe-MOFs）were synthesized by one-step method as the support platform to enhance the conductivity and immobilize more biotin-modified capture probe（bio-CP）through the superior affinity and specificity between streptavidin and biotin.Next,Cerium dioxide（CeO₂）-functionalzed carboxyl fullerene(c-C₆₀)supported by Pt nanoparticles(c-C₆₀/CeO₂/PtNPs)was prepared for signal amplification.c-C₆₀/CeO₂/PtNPs were labeled with signal probe to form the signal label.After the sandwich reaction of CYP2C19*2 gene between capture probe and the signal label,a distinguishing electrochemical signal from the catalysis of H₂O₂ by signal label would be observed.Amperometry was applied to record electrochemical signals to achieve the detect of CYP2C19*2 gene.Under optimized conditions,the approach showed a good linear dependence between current and the logarithm of CYP2C19*2 gene concentrations in the range of 1 fM to 50nM with a low detection limit of 0.33 fM（S/N=3）.The proposed method showed good specificity to target DNA compared with possible interfering substances.More importantly,the fabricated biosensor achieved accurate quantitative detection of CYP2C19*2 gene in human serum samples and provided a promising strategy for rapid detection of gene mutations.2.An light-electricity dual signal sensor for the detection of PCSK9 using s-PdNFs as a signal labelProprotein convertase subtilisin/kexin type 9（PCSK9）can be used the marker of atherosclerosis.Thus,design an effective method to detect serum PCSK9 is meaningful for the prevention and monitoring of cardiovascular diseases.Here,we reported that a signal label,sulphur-doped palladium nanoflowers（s-PdNFs）,used for multi-signal material,due to its multifunctional properties of quenching and catalysis.Thus,we design a dual signal method to detect serum PCSK9.First,we firstly found that s-PdNFs can effectively quench the ECL intensity of peroxydisulfate/oxygen(S₂O₈^2-/O₂)system via ECL resonance energy transfer（ECL-RET）and constructed a ECL immunosensor channel.In addition,s-PdNFs produce electric signals by catalyzing H₂O₂ due to its peroxidase-like activity.Here,a novel electrochemical immunosensor channel was constructed based on s-PdNFs as signal label.The two channels are integrated into one sensing interface,and a ultrasensitive light-electricitydual-signalimmunosensorwasachieved.The immunosensor could specifically,accurately,and ultrasensitively detect PCSK9 with a broad linear range of 5 fg mL^-11 to 50 ng mL^-1（ECL channel）and 500 fg mL^-11 to 50 ng mL^-1（electrochemical channel）.Furthermore,the ECL channel and electrochemical channel can achieve the detection respectively which can meet different testing instruments.The two channel can also be combined to judge the results to improve the accuracy of the detection.More importantly,the immunosensor realized the detection of PCSK9 in real serum samples demonstrated by good correlations with ELISA method.Our findings provide relevant experimental data for the application of multifunctional materials in sensor field.