Studies On Electrochemiluminescence Biosensor Based On Novel Coreactant And Nanomaterials Signal Amplification Technology

Electrochemiluminescence（ECL）technology is an emerging technology combining advantages of traditional electrochemical and chemiluminescence,with fast,high controllability,high sensitivity,wide linear range.The ECL technique has been widely utilized in clinical,pharmaceutical,environmental,food analysis and so on.Owing to the strong emission,low cost,and low oxidation potential,luminol become the most extensively applied ECL luminophor.However,traditional coreactants have the disadvantages of biological toxicity,difficult labeling,instability,and easy decomposition,which limits the application of the luminol system in the field of ECL.So far,works involving new coreactant of luminol are rarely reported.In order to improve the performance of the luminol system,the development of stable,low-toxic and highly efficient new coreactant for the construction the luminol system has become an urgent problem.Nanomaterials with characteristics of large specific surface area,high catalytic activity,and good electrical conductivity show broad application on biosensors.Replacing traditional coreactant with new coreactant and combining with the excellent properities of nanomaterials,it not only can overcome the shortcomings of traditional coreactant to optimize the luminol/ECL system,but also achieve the secondary amplification of the luminescence signal.Therefore,the article uses metal/transition metal nanomaterials and carbon nanomaterials as nanocarreir of luminophor and new coreactants with excellent performance to construct stable and sensitive biosensors for the determination of disease markers（glutathione,concanavalin,cytochrome c）.The specific research content is as follows:1.A novel electrochemiluminescence biosensor for glutathione determination based on poly-L-lysine as coreactant and graphene-based poly（luminol/aniline）as nanoprobesIn this study,functional poly（lumino/aniline）load on reduced graphene oxide（PLA-r GO）nanocomposites are prepared by in suit growthy method using ammonium persulfate（（NH₄）₂S₂O₈）as an initiator.A ECL biosensor based on the nanocomposite as signal probe and poly-L-lysine（PLL）as coreactant of luminol is constructed for sensitive determination of glutathione（GSH）.With a large specific surface area,reduced graphene oxide（r GO）can load amount of PLA,resulting in ECL signal amplification.Polyaniline（PANI）owing to excellent conductivity effectively enhances the conductivity of luminol.r GO with large specific surface area can increase the load of the luminophore and effectively reduce the adverse effects of non-solid space factors on the ECL reaction efficiency.Moreover,stable,low-toxic PLL as efficient coreactant obviously enhance the ECL intensity of the PLA-r GO.Therefore,ECL signal is multi-amplified and the sensitivity of the sensor is greatly improved.Based on significant quenching effect of GSH,the luminescence signal is significantly reduced.In the range of 1.0×10^-9 to 1.0×10^-4 mol·L^-1 and 1.0×10^-4 to 1.0×10^-2 mol·L^-1,the ECL intensity of biosensor shows a good linear relationship with the concentration of GSH,and the detection limit is 0.77 nmol·L^-1.2.An electrochemiluminescence analytical platform based on boron nitride quantum dots as novel coreactant for quantitative determination of Concanavalin AIn this work,a novel ECL biosensor is firstly constructed using low-cost,low-toxicity,high-stability boron-nitrogen quantum dots（BNQDs）as coreactant and PLA-r GO as effecient signal probe and electroactive substance carrier for selective determination of Concanavalin A.Cheap and stable BNQDs can not only effectively enhance the ECL signal of PLA-r GO/BNQDs system,reduce the cost of sensor preparation,but also realize the detection of target in a relatively mild environment,effectively expand the practical applications.Based on specific carbohydrate-lectin affinity,a ECL biosensor for selective determination of Concanavalin A.Due to significant electronic impedance effect of Con A,ECL intensity of luminol significantly decrease.In the range of 1.0 pg m L^-1 to 1.0μg m L^-1,the ECL intensity of biosensor shows a good linear relationship with the concentration of the ECL intensity of biosensor shows a good linear relationship with the concentration of Con A,and a low detection limit of 0.15 pg m L^-1.3.Gold nanoparticle functionalized cobalt-nickel phosphate 3D nano-ice creams to fabricate stable and sensitive biosensor for cytochrome c assayCobalt-nickel phosphate 3D nano-ice creams（Co₃Ni₃（PO₄）₄ NICs）are synthesized by hydrothermal method and functionalized by Polyethyleneimine（PEI）.Then,gold nanoparticles（Au NPs）functionalized cobalt-nickel phosphate 3D nano-ice creams（Au@Co₃Ni₃（PO₄）₄ NICs）are prepared successfully through a facile Au-N Weak interaction.A stable and sensitive biosensor is proposed based on nanohybrids functionlized luminol（LH-Au@Co₃Ni₃（PO₄）₄）as signals probe and BNQDs)as coreactant in the neutral condition.Due to the large specific surface area and excellent electrocatalytic activity,Au@Co₃Ni₃（PO₄）₄ NICs can support more luminphor and catalyze the production of more free radical intermediates,enhancing emission of luminol.Moreover,Co₃Ni₃（PO₄）₄ NICs containing rich negatively charges,can prevent the deposition of negatively charged oxidation product induced electrode passivation.Owing to the resonance energy transfer（RET）between luminol as donor and Cytochrome c as accepter,the ECL emission of luminol is obviously quenched.Hence,a sensitive ECL biosensor is successfully fabricated for the quantitative determination of Cyt c in cell lysates and exhibits wide linear ranges of 1.0×10^-4 to 0.5×10^-5 mol·L^-1and 0.5×10^-5 to 1.0×10^-8 mol·L^-1,as well as a low detection limit of 2.48 nmol·L^-1.