title: Size-tunable Pt nanoparticles assembled on functionalized ordered mesoporous carbon for the simultaneous and on-line detection of glucose and L-lactate in brain microdialysate.
abstract: This study presents a facile electrochemical method for simultaneous and selective on-line detection of glucose and L-lactate in the striatum of anesthetic rats through the integration of selective electrochemical detection with in vivo microdialysis system. A positively-charged polyelectrolyte, (diallyldimethylammonium chloride) (PDDA), was attached onto carbon mesoporous material (CMM) through non-covalent interaction, which provided an ideal environment for the assembling and dispersion of nanoparticle electrocatalysts. Platinum nanoparticles with wide loadings from 5 to 50 wt% were successfully self-assembled on PDDA-functionalized CMM via electrostatic interaction. TEM results showed that with the increase in the Pt loadings, both the size and interconnectivity between particles increased, with particle sizes ranging from 3.2±0.4 to 6.8±1.4 nm. Moreover, the electrocatalytic activities of the as-prepared six Pt/PDDA-CMM hybrid nanocomposites were also observed to show an inverted-V-shaped profile as a function of loading amount of Pt NPs. Integrated with glucose oxidase (GOx), L-lactate oxidase (LOD) and the in vivo microdialysis system, the constructed dual oxidase/Pt/PDDA-CMM/Nafion biosensors were successfully applied for the simultaneous and on-line detection of glucose and L-lactate. After post-calibration, the basal level of glucose and L-lactate in the striatum of anesthetic rats was calculated to be 0.27±0.03 and 0.71±0.05 mM (mean ±s.d., n=3), respectively. What is more important, the dual oxidase biosensors almost suffered from little cross-talk, which is characteristic of an excellent sensor with high performance. This property, along with the good linearity and a high stability substantially enables this method promising application in physiology and pathology.
authors.affiliation: Department of Chemistry and Shanghai Key Laboratory of Green Chemistry and Chemical Process, East China Normal University, 500 Dongchuan Road, Shanghai 200241, PR China.
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Yu
authors.forename: Yan
authors.initials: Y
authors.lastname: Yang
authors.forename: Hui
authors.initials: H
authors.lastname: Gu
authors.forename: Tianshu
authors.initials: T
authors.lastname: Zhou
authors.forename: Guoyue
authors.initials: G
authors.lastname: Shi
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation*; D001923:Brain Chemistry; D002244:Carbon / Q000737:chemistry; D003217:Conductometry / Q000295:instrumentation*; D004800:Enzymes, Immobilized / Q000737:chemistry; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005947:Glucose / Q000032:analysis*; D005949:Glucose Oxidase / Q000737:chemistry*; D019344:Lactic Acid / Q000032:analysis*; D053768:Metal Nanoparticles / Q000737:chemistry*; D017551:Microdialysis / Q000295:instrumentation; D008839:Microelectrodes; D010984:Platinum / Q000737:chemistry; D016062:Porosity; D051381:Rats; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D004800:Enzymes, Immobilized; D019344:Lactic Acid; D010984:Platinum; D002244:Carbon; D005949:Glucose Oxidase; D005947:Glucose