ABSTRACT
An electrochemical L-lactate biosensor was fabricated by combining Platinum nanoparticles (Pt-nano) with multi-walled carbon nanotubes(MWCNTs).L-lactate oxidase(LOD) was immobilized on the surface of the glassy carbon electrode (GCE) modified with MWCNTs and Pt-nano.The surface of resulting LOD/MWCNTs/Pt-nano electrode was covered by a thin layer of sol-gel to avoid the loss of LOD and to improve the anti-interference ability.The cyclic voltammetric results indicated that MWCNTs/Pt-nano catalyst displayed a higher performance than MWCNTs.Under the optimized conditions, i.e., applied potential of 0.5 V, pH 6.4, 25 ℃, the proposed biosensor's determination range was 0.2-2.0 mmol/L, response time was within 5 s, and the sensitivity was 6.36 (A/(mmol/L).It still kept 90% activity after 4 weeks.The fabricated biosensor had practically good selectivity against interferences.The results for whole blood samples analyzed by the present biosensor showed a good agreement with those analyzed by spectrophotometric method.
ABSTRACT
Objective To study the relationship between portal hypertension(PHT) and heme oxygenase-1(HO-1)mRNA expression in rats.Method An animal model of PHT induced by partial portal vein constriction was established to detect the expression of HO-1mRNA in the liver,spleen, and splenic vein of rats by situ hybridization method. Result HO-1mRNA was not detected in the liver, spleen, and splenic vein in the control group. In PHT rats, HO-1mRNA was not detected in the liver;but in the spleen,the expression of HO-1mRNA was 83.3%;in the splenic vein,the expression was 55.6%. Conclusions The PHT rat is in stress condition.The expression of HO-1mRNA in the spleen and splenic vein of PHT ratsare increased and the metabolic product of HO-1 may exacerbate the PHT.