pH Value Of Buffer Solution Research Articles

Phenylboronic Acid Appended Pyrene-Based Low-Molecular-Weight Injectable Hydrogel: Glucose-Stimulated Insulin Release.

A pyrene-containing phenylboronic acid (PBA) functionalized low-molecular-weight hydrogelator was synthesized with the aim to develop glucose-sensitive insulin release. The gelator showed the solvent imbibing ability in aqueous buffer solutions of pH values, ranging from 8-12, whereas the sodium salt of the gelator formed a hydrogel at physiological pH 7.4 with a minimum gelation concentration (MGC) of 5 mg mL(-1) . The aggregation behavior of this thermoreversible hydrogel was studied by using microscopic and spectroscopic techniques, including transmission electron microscopy, FTIR, UV/Vis, luminescence, and CD spectroscopy. These investigations revealed that hydrogen bonding, π-π stacking, and van der Waals interactions are the key factors for the self-assembled gelation. The diol-sensitive PBA part and the pyrene unit in the gelator were judiciously used in fluorimetric sensing of minute amounts of glucose at physiological pH. The morphological change of the gel due to addition of glucose was investigated by scanning electron microscopy, which denoted the glucose-responsive swelling of the hydrogel. A rheological study indicated the loss of the rigidity of the native gel in the presence of glucose. Hence, the glucose-induced swelling of the hydrogel was exploited in the controlled release of insulin from the hydrogel. The insulin-loaded hydrogel showed thixotropic self-recovery property, which hoisted it as an injectable soft composite. Encouragingly, the gelator was found to be compatible with HeLa cells.

Simultaneously determination of trace Cd2+ and Pb2+ based on l-cysteine/graphene modified glassy carbon electrode

In this paper, l-cysteine/graphene–CS/GCE (l-cys/GR–CS/GCE) was prepared successfully, and its electrochemical properties were characterized by cyclic voltammetry (CV) and electrochemical AC impedance. Moreover, the electrochemical behaviors of Cd2+ and Pb2+ on the proposed electrode were studied by differential pulse anodic stripping voltammetry (DPASV). Experimental parameters, such as the deposition potential and time, the pH value of buffer solution, were optimized. Under the optimized conditions, the linear equations of the DPASV response current with Cd2+ and Pb2+ concentration were I (μA)=0.745C (μg/L)+4.539 (R=0.9986), I (μA)=0.437C (μg/L)+2.842 (R=0.9983), respectively, and the detection limit was 0.45 and 0.12μg/L, respectively. Finally, l-cys/GR–CS/GCE was used to detect Cd2+ and Pb2+ in practical samples, and the results were compared with ICP-AES. This idea and method will provide a new approach for food security evaluation.

Adsorption of virus-like particles on ion exchange surface: Conformational changes at different pH detected by dual polarization interferometry

Disassembling of virus-like particles (VLPs) like hepatitis B virus surface antigen (HB-VLPs) during chromatographic process has been identified as a major cause of loss of antigen activity. In this study, dual polarization interferometry (DPI) measurement, together with chromatography experiments, were performed to study the adsorption and conformational change of HB-VLPs on ion exchange surface at three different pHs. Changes in pH values of buffer solution showed only minimal effect on the HB-VLPs assembly and antigen activity, while significantly different degree of HB-VLPs disassembling was observed after ion exchange chromatography (IEC) at different pHs, indicating the conformational change of HB-VLPs caused mainly by its interactions with the adsorbent surface. By creating an ion exchange surface on chip surface, the conformational changes of HB-VLPs during adsorption to the surface were monitored in real time by DPI for the first time. As pH increased from 7.0 to 9.0, strong electrostatic interactions between oppositely charged HB-VLPs and the ion exchange surface make the HB-VLPs spread thinly or even adsorbed in disassembled formation on the surface as revealed by significant decrease in thickness of the adsorbed layer measured by DPI. Such findings were consistent with the results of IEC experiments operated at different pHs, that more disassembled HB-VLPs were detected in the eluted proteins at pH 9.0. At low pH like pH 5.0, however, possible bi-layer adsorption was involved as evidenced by an adsorbed layer thickness higher than average diameter of the HB-VLPs. The “lateral” protein–protein interactions might be unfavorable and would make additional contribution to the disassembling of HB-VLPs besides the primary mechanism related to the protein–surface interactions; therefore, the lowest antigen activity was observed after IEC at pH 5.0. Such real-time information on conformational change of VLPs is helpful for better understanding the real mechanism for the disassembling of VLPs on the solid–liquid interface.

Voltammetric Sensing of Endocrine Disruptor (Bisphenol A) Based on a Reduced Graphene Oxide/Carbon Nanotube/Gold Nanoparticles Nanocomposite Modified Screen-Printed Electrode

Bisphenol A (BPA) (2,2-bis(4-hydroxyphenyl propane, C15H16O2) is a key monomer ubiquitously used in the production of polymers, polycarbonate plastics, sealants, epoxy resins, the lining of food cans etc1. However, BPA could potentially interfere with the endocrine system of humans and is believed to be indicated in diverse pleiotropic actions in the brain and cardiovascular systems, various kinds of cancer, reproductive disorders, obesity, and birth defects, etc1. Given the deleterious effects of BPA and its omnipresent presence in our daily life, the development of a rapid, simple and sensitive analytical method for BPA measurement is critical. Several approaches are used to determine BPA2, which include but not limit to liquid chromatography-mass spectrometry (LC-MS), gas chromatography-mass spectrometry (GC-MS), enzyme-linked immunosorbent assay (ELISA), and liquid chromatography-electrochemical detector (LC-ECD). Although these methods could detect BPA sensitively, complex, time-consuming sample preparation protocols and expensive equipment used are major disadvantages. Electrochemical methods, on the other hand, are rapid, inexpensive, simple, and highly sensitive; moreover, they are amenable for fabrication of portable units. Herein, we present a facile and green approach to fabricate a highly sensitive electrochemical sensor for the determination of BPA in aqueous solution by using reduced graphene oxide (RGO), carbon nanotubes (CNT), and gold nanopaticles (AuNPs) modified screen-printed electrode (SPE). Graphene oxide (GO)/CNT nanocomposite was first deposited onto SPE, then electrochemically reduced to RGO/CNT at room temperature. Subsequently, AuNPs were electrochemically deposited in situ on RGO/CNT modified SPE. The morphology of bare SPE, GO/CNT-modified SPE, and RGO/CNT/AuNPs-modified SPE was characterized by scanning electron microscopy (SEM). Figures 2a, b, and c displays the SEM images of the working electrode part of bare SPE, GO/CNT-modified SPE, and RGO/CNT/AuNPs-modified SPE, respectively. The bare SPE, shows sheet-like structures with many small particles dispersed throughout (Figure 2a). These structures can be assigned as graphitic carbon powder, according to the composition of the electrode. Figure 2b demonstrates the CNT could improve the surface roughness and potentially bridge the graphene sheet and small particles of graphitic powder. After electrodeposition of AuNPs, the AuNPs are seen evenly distributed in the RGO/CNT network (Figure 2c). Based on particle size analysis of at least 100 particles in SEM images, the average size of AuNPs was 84.6 ± 23.6 nm. Figure 3a displays the cyclic voltammograms of ferri/ferrocyanide solution at bare, GO/CNT-, RGO/CNT-, and RGO/CNT/AuNPs-modified SPEs. The electrochemical response at the bare SPE (at 50 mV·s-1scan rate) displays a relatively slow electron transfer and an irreversible electrochemical process. When modified with GO/CNT, the peak separation increased along with a reduction in the redox peak current. After GO is reduced to RGO (i.e., became RGO/CNT modified SPE), as expected, the redox peak current raised with a much smaller peak separation, which implies that most of the oxygenated groups on GO were removed and electron transfer was improved. The electrochemical response was further significantly enhanced after the electrodeposition of AuNPs, which is attributable to the extraordinary catalytic ability, large surface-to-volume ratio, and excellent electrical conductivity of the AuNPs. Several important parameters, such as accumulation potential and time of differential pulse voltammetry, and pH value of buffer solution were investigated and optimized. Under the optimized conditions, the oxidation peak current in differential pulse voltammograms was proportional to BPA concentration in the range of 1.45 to 20 and 20 to 1,490 nmol/L of BPA, with an ultralow detection limit of 800 pmol/L (at signal/noise=3). Figure 1. Fabrication of RGO/CNT/AuNPs modified SPE Figure 2. SEM images of (a) bare, (b) GO/CNT-modified, and (c) RGO/CNT/AuNPs-modified SPEs Figure 3. (a) Cyclic voltammograms at bare and GO/CNT-, RGO/CNT-, and RGO/CNT/AuNPs-modified SPEs. (b) Peak currents for BPA detection in two linear ranges of 1.45 to 20 nM and 20 to 1,490 nM. Inset is an expanded view of measurements of 1.45 to 20 nM BPA.

Preparation and characterization of chitosan gel beads crosslinked by organic titanium

Chitosan (CTS) gel was successfully prepared by organic titanium (OT) ionic crosslinking agent. The viscoelastic properties of CTS gel was investigated through rheological measurement. The sol-gel transition point (t cr ) of gel prepared with CTS (22.5 g•L−1) and OT (1.5 %) was determined at 339 s, with the increases of either CTS or OT concentration, the gelation became faster and the sol-gel transition time became shorter. The optimal chitosan gel beads were prepared with 35 g•L−1 chitosan and 7 % organic titanium (OT) at room temperature for 1 h reaction. The SEM data indicated that the gel beads had special shape with rough and poriferous surface. The effective grain size range was 1.0–1.2 mm. It was confirmed by TG data that the gel beads performed better in thermal stability than original chitosan. Swelling experiments showed that the swelling ability of gel beads strongly depended on the pH value of buffer solution. On the whole, the modified CTS/OT gel beads showed high adsorption capacity, good mechanical properties, strong acidic and alkali resistances, it could serve as potential drug deliver and the absorbent for heavy metal ions.

Determination of Trace 1-Hydroxypyrene by Resin MN202 With Graphene Composite Modified Glassy Carbon Electrode

1-hydroxypyrene (1-OHP) is a kind of polycyclic aromatic hydrocarbons (PAHs) metabolites and has been used widely as a biomarker for evaluating human exposure to PAHs. In this paper, an electrochemical sensor was fabricated based on graphene-MN202 modified glassy carbon electrodes and used to preconcentrate and detect 1-OHP. When 1-OHP was preconcentrated on modified electrodes, the response signals and adsorption stability were enhanced. The electrochemical characteristics of 1-OHP on the modified electrode were investigated by cyclic voltammetry and differential pulse voltammetry. Experimental parameters were optimized, such as the adsorption potential, adsorption time, scan rate, and the pH values of buffer solution. Under the optimized conditions, the peak current was proportional to 1-OHP concentration in a wide range from 0.005 to 12.0 μm ol/L, and the detection limit was 1.72 nmol/L (S/N = 3). Moreover, the fabricated electrode also exhibited good reproducibility and stability, and can be employed to determinate 1-OHP, which is in human urine in situ successfully.

The Process Conditions of Extracting Polysaccharides from <i>Dendrocalamus latiflorus</i> by Cellulase

The study is focused on the extracting polysaccharide from Dendrocalamus latiflorus with assisted enzyme and cool water to maintain its biological activity. The optimized conditions for the cellulase process are listed as follows The enzymatic hydrolysis temperature stays 50°C. The mass fraction of cellulase (MFC) is 0.4% on the basis of the mass of dry leaves. The volume of water added in is 20mL on the basis of the mass of dry leaves and the pH value of buffer solution remains 4.6. Under these conditions, the ratio of polysaccharides (RP) can be 0.92% after two extractions for 180min in total and its RP is 12.05% higher than the traditional process.

Selective Detection by Dpv of Benserazide and Levodopa in Pharmaceutical Preparates

For the detection of some important biological substances by electrochemical methods the carbon modified electrodes have been widely used [1-3]. The aim of this work was to study the simultaneous detection of benserazide and levodopa in pharmaceutical tablets of MADOPAR® by the voltammetric method using a modified C-PVC electrode. The preparation and modification of the C-PVC electrode was performed according to the previously reported method [4]. The tablet extract in presence of excipients of MADOPAR® in phosphates buffer pH 7.4 was used for the measurements without pretreatment. The electrochemical experiment by VDP of the MADOPAR®extract using the C-PVC modified electrode showed good defined oxidation peaks for benserazide at 24 mV and levodopa at 141 mV. The oxidation current was proportional to the volume of the extract in the buffer solution (Fig.1). The presence of an excess of ascorbic acid (140 µM) did not affect the detection of benserazide and levodopa. The modified C-PVC electrode can be used for the simultaneous determination of benserazide and levodopa in some real samples at different pH values of buffer solutions.

A facial electrochemical approach to determinate bisphenol A based on graphene-hypercrosslinked resin MN202 composite

It first reported a novel electrochemical approach for the in situ determination of bisphenol A (BPA) in the milk and mineralised water using graphene-hypercrosslinked resin MN202 composite (MN202) modified electrode. The electrocatalytic oxidation and electroanalytical of BPA on the modified electrode were investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). It is notable that the oxidation peak current of BPA had enhanced remarkably and the oxidation overpotential had decreased significantly. Experimental parameters, such as the accumulation potential and time, scan rate, and the pH value of buffer solution were optimised. Under the optimised conditions, the oxidation peak current was proportional to BPA concentration in a wide range between 0.005 and 20.0μmol/L, and the detection limit was 1.02nmol/L (S/N=3). Moreover, the fabricated electrode also exhibited good reproducibility and stability, and employed to in situ determinate BPA in milk and mineralised water successfully.

Differential pulse striping voltammetric determination of molluscicide niclosamide using three different carbon nanomaterials modified electrodes

Three different carbon nanomaterials modified electrodes based on single(multi)-walled carbon nanotubes (S(M)WCNTs) and electrochemically reduced graphene oxide (ER-GO) modified glassy carbon electrodes (GCE) were fabricated and used to investigate the electrochemical behavior of niclosamide (NA) by cyclic voltammetry and differential pulse anodic stripping voltammetry. Experimental parameters, such as the preconcentration time, scan rate, and the pH value of buffer solution were optimized. A possible working mechanism for the electrochemical detection of NA was also proposed. The electrochemical performances of these three carbon nanomaterials modified electrodes were compared with one another. Among three modified electrodes, ER-GO/GCE displayed lowest peak potential, highest sensitivity, best repeatability, reproducibility and peak shape as well as higher peak current response. Additionally, ER-GO/GCE exhibited better linearity than S(M)WCNTs/GCE over ranges from 0.020 to 23.1μM with the detection limit of 6.6nM (S/N=3), and also successfully employed for real sample analysis with NA tablets. Satisfactory results indicated that ER-GO/GCE can provide a promising candidate for the trace analysis of NA in agriculture.

Enantiomeric separation of sitagliptin by a validated chiral liquid chromatographic method

An enantioselective reversed phase high performance liquid chromatographic method was developed and validated. The enantiomers of sitagliptin were resolved on a Chiralcel OD-RH (150 mm × 4.6 mm, 5 μm) column using a mobile phase system containing 3 M potassium di-hydrogen phosphate buffer (pH 4.0)–methanol–acetonitrile (60:30:10, v/v/v). The resolution between the enantiomers was not less than 3.0. The pH value of buffer solution in the mobile phase played a key role in enhancing chromatographic efficiency and resolution between the enantiomers. The developed method was validated according to ICH guidelines. The calibration curve was found to be linear over the concentration range of 30–300 ng mL−1 (r2 = 0.9996). The limit of detection and limit of quantification of the (S)-enantiomer were found to be 8 and 30 ng mL−1, respectively, for 20 μL injection volume. The percentage recovery of the (S)-enantiomer ranged from 99.06 to 100.2 in bulk drug samples of sitagliptin. The sample solution and mobile phase were found to be stable at least for 48 h. The final optimized method was successfully applied to separate the (S)-enantiomer from sitagliptin and was proved to be reproducible, accurate and robust for the quantitative determination of the (S)-enantiomer in bulk drugs.

Hydorgen Peroxide Biosensor Based on Direct Electrochemistry of Hemin in Egg–Phosphatidylcholine Films

Abstract The mixture of egg-PC vesicles and hemin was casted onto indium-tin oxide glass (ITO) electrode. The hemin showed a direct electrochemical behavior on the modified electrode. A well-defined pair of redox peaks was obtained from the cyclic voltammograms at ITO electrode modified by the mixture of hemin and egg-phosphatidylcholine (egg-PC). The average value of the surface coverage of electroactive hemin, Γ, was 3.25 × 10 −12 mol cm −2 . The formal potential ( E o ') of hemin in the lipid film was linearly varied with the pH of phosphate buffer solution in the range from 4.0 to 9.0 with a slope of −43.7 mV/pH. The pH value of buffer solution for measuring hydrogen peroxide was decided to be 4.0. The linear range of the biosensor was from 10 μM to 200 μM with a detection limit of 5 μM. The modified electrode exhibited a good catalytic activity towards hydrogen peroxide. Therefore a third generation biosensor was developed.

Electrochemical Determination of 4-Nonylphenol on Graphene-Chitosan Modified Glassy Carbon Electrode

Abstract In this stady, a graphene-chitosan (GR-CS) modified glassy carbon electrode (GCE) was prepared by in situ reduction. The obtained electrode was characterized by FT-IR spectroscopy and Raman spectroscopy, and the results showed that the graphene oxide (GO) was deoxygenized successfully. On this basis, the electrochemical behavior of 4-nonylphenol (4-NP) was studied by using cyclic voltammetry and differential pulse voltammetry. It was found that the oxidation current on GR-CS/GCE electrode was significantly larger than on the GCE and GO-CS/GCE electrodes. The oxidation potential shifted negatively, indicating that the GR-CS/GCE electrode had obviously catalytic activity on the 4-NP's oxidation. Experimental parameters, such as the accumulation potential and time, scan rate, and pH value of buffer solution were optimized. Under the optimized conditions, the oxidation peak current was proportional to 4-NP concentration in the range between 0.01–40.0 μM, the linear equation was I (μA) = 0.364 C (μM) + 0.618 ( R = 0.9988), and the detection limit was 0.0052 μM ( S/N = 3). Finally, this proposed sensor was successfully employed to determine 4-NP in real samples with the recoveries ranging in 95.0%–101.0%.

Determination of p-nitrophenol on carbon paste electrode modified with a nanoscaled compound oxide Mg(Ni)FeO

A novel electrochemical sensor for the determination of p-nitrophenol (PNP) was fabricated with the nanoscaled composite oxide Mg(Ni)FeO-modified carbon paste electrode (CPE), and its electrocatalytic performances were investigated using the cyclic voltammogram and differential pulse voltammetry techniques. The influential factors were optimized such as the mass ratio of Mg(Ni)FeO to graphite, the pH value of buffer solution and the accumulation time at open circuit. The indirect oxidation peak current of PNP was found to be proportional to its concentration between 2.0 × 10−6 and 2.0 × 10−4 M on the proposed sensor Mg(Ni)FeO/CPE under the optimal condition (10 % Mg(Ni)FeO/graphite, pH 5.0 HAc–NaAc, 120 s quiescence). The sensor Mg(Ni)FeO/CPE exhibited a high sensitivity of 811 μA mM−1 cm−2 and a low detection limit of 0.2 μΜ (S/N– = 3) for PNP detection, and got satisfactory results when it was applied to determine PNP in real samples. The results demonstrate that Mg(Ni)FeO/CPE based on the nanomaterial Mg(Ni)FeO with high specific area and mesoporous structure could be employed as an electrochemical sensor for PNP determination with simplicity, low cost, good selectivity, repeatability, and stability.

Polyol induced interpenetrating networks: chitosan-methylmethacrylate based biocompatible and pH responsive hydrogels for drug delivery system.

Biodegradable and biocompatible hydrogels are a fairly imperative class of biomaterials, which find applications for drug delivery. The blending of natural biopolymers and synthetic polymers has introduced exceptional characteristics in hydrogels for diverse biomedical applications. Here, we report a novel class of pH responsive, hydrophobically modified chitosan based hydrogels using methylmethacrylate (MMA) and sustainable polyol. The polyol derivatized hydrogels were characterized using FT-IR spectroscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The biodegradability studies were carried out in soil and water. The in vitro equilibrium swelling behavior in different buffer solutions of pH values (4 and 7.3), including some physiological solutions were also evaluated. The potential of these hydrogels in drug delivery was demonstrated by preliminary biocompatibility assessment in different human sera for 24 hours. No significant changes in the values of various components present in sera before and after test procedures were found.

Hydrogen Peroxide Biosensor Based on Direct Electrochemistry of Hemin in Egg-Phosphatidylcholine Films

The mixture of egg-phosphatidylcholine( PC) vesicles and hemin was casted onto indium-tin oxide glass( ITO) electrode. The hemin showed a direct electrochemical behavior on the modified electrode. A welldefined pair of redox peaks was obtained from the cyclic voltammograms at the mixture of hemin and egg-PC modified ITO electrode. The average value of the surface coverage of electroactive hemin,Γ,was equal to3. 25 × 10!12mol / cm2. The formal potential( Eo') of hemin in the lipid film was linearly varied with the pH of phosphate buffer solution in the range from 4. 0 to 9. 0 with a slope of 43. 7 mV / pH. The pH value of buffer solution for measuring hydrogen peroxide was decided to be 4. 0. The linear range of our biosensor was from10 μmol / L to 200 μmol / L with a detection limit of 5 μmol / L. The modified electrode exhibited a good catalytic activity towards hydrogen peroxide. Therefore a third generation biosensor was developed.

Fabrication of Silicon Nitride Ion Sensitive Field‐Effect Transistor for pH Measurement and DNA Immobilization/Hybridization

The fabrication of ion sensitive field‐effect transistor (ISFET) using silicon nitride (Si3N4) as the sensing membrane for pH measurement and DNA is reported. For the pH measurement, the Ag/AgCl electrode was used as the reference electrode, and different pH values of buffer solution were used in the ISFET analysis. The ISFET device was tested with pH buffer solutions of pH2, pH3, pH7, pH8, and pH9. The results show that the IV characteristic of ISFET devices is directly proportional and the device’s sensitivity was 43.13 mV/pH. The ISFET is modified chemically to allow the integration with biological element to form a biologically active field‐effect transistor (BIOFET). It was found that the DNA immobilization activities which occurred on the sensing membrane caused the drain current to drop due to the negatively charged backbones of the DNA probes repelled electrons from accumulating at the conducting channel. The drain current was further decreased when the DNA hybridization took place.

Sensitive determination of bisphenol A base on arginine functionalized nanocomposite graphene film

Arginine (Arg) functionalized graphene (Arg-G) nanocomposite was produced successfully by an environment-friendly method, and the morphology of the nanocomposite was characterized by transmission electron microscopy (TEM), Raman spectra, etc. Based on Arg-G nanocomposite, an electrochemical sensor was fabricated for sensitive detection of bisphenol A (BPA). The electrochemical behaviors of BPA on Arg-G modified glassy carbon electrode (GCE) were investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Experimental parameters, such as the accumulation potential and time, scan rate, and the pH value of buffer solution were optimized. Under the optimized conditions, the oxidation peak current was proportional to BPA concentration in the range between 5.0nmol/L and 40.0μmol/L with the correlation coefficient of 0.9986 and the limit of detection of 1.1nmol/L (S/N=3). Moreover, the fabricated electrode also exhibited good reproducibility and stability. The proposed sensor was successfully employed to determine BPA in real plastic products and the recoveries were satisfactory.

Cathodic electrochemiluminescence of luminol using polyaniline/ordered mesoporous carbon (CMK-3) hybrid modified electrode for signal amplification

A highly porous three-dimensional sensing interface was achieved on glassy carbon (GCE) by employing ordered mesoporous carbon (OMC) and polyaniline (PANI). Compared with the cathodic electrochemiluminescence (ECL) of luminol at bare glassy carbon electrode, a stable and intense cathodic ECL emission of luminol over −0.5V which related to the reduction of dissolved oxygen in solution was triggered at OMC and PANI constructed ECL sensing platform. The influence factors affecting the electrode configuration such as the concentration of OMC, the dripping amount of OMC, the polymerization cycles of PANI and the pH value of buffer solution on cathodic ECL intensity of luminol were investigated in detail. The PANI/CMK composite modified electrode exhibited an effective ECL platform for cathodic ECL of luminol due to its attractive features, such as excellent electrical conductivity, extremely well-ordered pore structure and high specific pore volume. The possible ECL mechanism was discussed according to the presented experimental results.

Towards understanding of protein adsorption behavior on plasma polymerized pyrrole film

Abstract Plasma polymerized pyrrole-like (PPpy) films exhibit good environmental stability and offer high reactivity with biomolecules. The present paper follows on from previous work on PPpy films applied as DNA immobilization/hybridization and describes the adsorption kinetics of bovine serum albumin (BSA) on PPpy films. Atom force microscopy was used to detect the surface roughness of PPpy surfaces obtained at different input powers or for different polymerization time, including the surface roughness before and after BSA adsorption. The influence of experimental conditions (i.e., the plasma input power, the polymerization time, the concentration of BSA, and the pH values of buffer solutions) on protein adsorption was investigated in situ by Surface plasmon resonance spectroscopy (SPR). SPR analysis confirmed the differently dynamic adsorption behavior of BSA on PPpy films under various experimental conditions. The adsorption constant, K a , was deduced from Langmuir isotherm equations, which were simulated using experimental data collected by SPR and electrochemical impedance spectroscopy (EIS). Analysis of the combination data of SPR and EIS indicates that PPpy films under various conditions show completely different adsorption behaviors and could be applied as biomaterials for electrochemical protein sensing or as protein-resistant.