An electrochemical quantitative method of protein is developed based on the interaction between bromocresol purple(BP) and proteins. In pH 4.5 Britton-Robinson(B-R) buffer solution,BP has a sensitive reductive peak at...An electrochemical quantitative method of protein is developed based on the interaction between bromocresol purple(BP) and proteins. In pH 4.5 Britton-Robinson(B-R) buffer solution,BP has a sensitive reductive peak at -0.518 V( vs. SCE) on the hanging mercury drop electrode. After adding human serum albumin(HSA) to the above solution,the reduction peak current of BP decreased apparently without the shift of the peak potential. The decrease of the reductive peak current of BP is proportional to HSA concentration in the range of 1.0—20.0 mg/L and 20.0—200.0 mg/L with the regression equation Δ I ″ p=90.87+150.53 c(r =0.997) and Δ I ″ p=3 063.70+9.05 c(r =0.992),respectively. The binding ratio of HSA with BP is 1∶2 and the binding constant β s=1.32×10 9. The proposed method was applied to determine the content of HSA in blood samples and the results are in accordance with the traditional Coomassie Brilliant Blue G-250 spectrophotometric assay. This method was further applied to the determination of bovine serum albumin,bovine hemoglobin,egg albumin etc. with satisfactory results.展开更多
It is well known that hydrogen peroxide in dilute H 2SO 4 solution discolorizes bromocresol purple, while oxalic acid can sensitively inhibit the discoloration reaction or slow the reaction rate. The kinetic beha- vio...It is well known that hydrogen peroxide in dilute H 2SO 4 solution discolorizes bromocresol purple, while oxalic acid can sensitively inhibit the discoloration reaction or slow the reaction rate. The kinetic beha- vior of the inhibition reaction has been investigated and a kinetic spectrometric method for determination of trace oxalic acid was developed with detection limit 2.8×10 -8 g/mL and the linear range of the determination was 0～8×10 -7 g/mL oxalic acid. ε 430=1.50×10 5 L/(mol·cm). The method has been satisfactorily applied to the determination of trace oxalic acid in fruits, greens and cereals.展开更多
pH-responsive 1O2 photosensitizing systems may serve as selective photodynamic therapy(PDT) agents by targeting the acidic interstitial fluid of many kinds of tumors.In this work,a natural and clinically used photosen...pH-responsive 1O2 photosensitizing systems may serve as selective photodynamic therapy(PDT) agents by targeting the acidic interstitial fluid of many kinds of tumors.In this work,a natural and clinically used photosensitizer(Hypocrellin B,HB) and a pH indicator(Bromocresol Purple,BCP) were co-encapsulated in organically modified silica nanoparticles.BCP successfully regulated the 1O2 generation efficiency of HB through the "inner filter" effect,which shows much stronger 1O2 generation ability in an acidic than in a basic environment.In vitro experiments also demonstrated that HB-doped nanoparticles are effective in killing tumor cells by PDT.展开更多
文摘An electrochemical quantitative method of protein is developed based on the interaction between bromocresol purple(BP) and proteins. In pH 4.5 Britton-Robinson(B-R) buffer solution,BP has a sensitive reductive peak at -0.518 V( vs. SCE) on the hanging mercury drop electrode. After adding human serum albumin(HSA) to the above solution,the reduction peak current of BP decreased apparently without the shift of the peak potential. The decrease of the reductive peak current of BP is proportional to HSA concentration in the range of 1.0—20.0 mg/L and 20.0—200.0 mg/L with the regression equation Δ I ″ p=90.87+150.53 c(r =0.997) and Δ I ″ p=3 063.70+9.05 c(r =0.992),respectively. The binding ratio of HSA with BP is 1∶2 and the binding constant β s=1.32×10 9. The proposed method was applied to determine the content of HSA in blood samples and the results are in accordance with the traditional Coomassie Brilliant Blue G-250 spectrophotometric assay. This method was further applied to the determination of bovine serum albumin,bovine hemoglobin,egg albumin etc. with satisfactory results.
文摘It is well known that hydrogen peroxide in dilute H 2SO 4 solution discolorizes bromocresol purple, while oxalic acid can sensitively inhibit the discoloration reaction or slow the reaction rate. The kinetic beha- vior of the inhibition reaction has been investigated and a kinetic spectrometric method for determination of trace oxalic acid was developed with detection limit 2.8×10 -8 g/mL and the linear range of the determination was 0～8×10 -7 g/mL oxalic acid. ε 430=1.50×10 5 L/(mol·cm). The method has been satisfactorily applied to the determination of trace oxalic acid in fruits, greens and cereals.
基金the financial support from the National Natural Science Foundation of China (20772133, 20873170)Chinese Academy of Sciences (KJCX2YWH08)
文摘pH-responsive 1O2 photosensitizing systems may serve as selective photodynamic therapy(PDT) agents by targeting the acidic interstitial fluid of many kinds of tumors.In this work,a natural and clinically used photosensitizer(Hypocrellin B,HB) and a pH indicator(Bromocresol Purple,BCP) were co-encapsulated in organically modified silica nanoparticles.BCP successfully regulated the 1O2 generation efficiency of HB through the "inner filter" effect,which shows much stronger 1O2 generation ability in an acidic than in a basic environment.In vitro experiments also demonstrated that HB-doped nanoparticles are effective in killing tumor cells by PDT.
