A new biocatalyst employing pyrenecarboxaldehyde as an anodic catalyst for enhancing the performance and stability of an enzymatic biofuel cell

Christwardana, Marcelinus,Chung, Yongjin,Kwon, Yongchai Nature Publishing Group (NPG) ; 2017 NPG Asia Materials Vol.9 No.-

<P>A new enzyme catalyst consisting of pyrenecarboxaldehyde (PCA) and glucose oxidase (GOx) immobilized on polyethyleneimine (PEI) and a carbon nanotube supporter (CNT/PEI/[PCA/GOx]) is suggested, and the performance and stability of an enzymatic biofuel cell (EBC) using the new catalyst are evaluated. Using PCA, the amount of immobilized GOx increases (3.3 U mg(-1)) and the electron transfer rate constant of the CNT/PEI/[PCA/GOx] is promoted (11.51 s(-1)). Also, the catalyst induces excellent EBC performance (maximum power density (MPD) of 2.1 mW cm(-2)), long-lasting stability (maintenance of 93% of the initial MPD after 4 weeks) and superior catalytic activity (flavin adenine dinucleotide redox reaction rate of 0.62 mA cm(-2) and Michaelis-Menten constant of 0.99 mM). These characteristics are ascribed to effects of (i) electron collection due to hydrophobic interactions, (ii) electron transfer pathways due to pi-conjugated bonds and (iii) enzyme stabilization due to p-hydrogen bonds that are newly induced by the PCA/GOx composite. The existence of such positive interactions is properly verified using X-ray photoelectron spectroscopy and enzyme activity measurements.</P>

Highly sensitive glucose biosensor using new glucose oxidase based biocatalyst

Marcelinus Christwardana,지정연,정용진,권용재 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.11

Glucose, which is a primary energy source of living organisms, can induce diabetes or hypoglycemia if its concentration in blood is irregular. It is therefore important to develop glucose biosensor that reads the concentration of glucose in blood precisely. In the present work, we suggest new glucose oxidase (GOx) based catalysts that can improve the sensitivity of the glucose biosensor and make glucose measurements over a wide concentration ranges possible. For synthesizing such catalysts, a composite including pyrenecarboxaldehyde (PCA) and GOx is attached to substrate including carbon nanotube (CNT) and polyethyleneimine (PEI) (CNT/PEI/[PCA/GOx]). Catalytic activity and stability of the catalyst are then evaluated. According to the investigation, the catalyst shows excellent glucose sensitivity of 47.83 μAcm−2mM−1, low Michaelis-Menten constant of 2.2mM, and wide glucose concentration detection, while it has good glucose selectivity against inhibitors, such as uric acid and ascorbic acid. Also, its activity is maintained to 95.7% of its initial value even after four weeks, confirming the catalyst is stable enough. The excellence of the catalyst is attributed to hydrophobic interaction, C=N bonds, and π-hydrogen interaction among GOx, PCA and PEI/ CNT. The bindings play a role in facilitating electron transport between GOx and electrode.

Glucose biofuel cells using the two-step reduction reaction of bienzyme structure as cathodic catalyst

Marcelinus Christwardana,정용진,김도형,권용재 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.71 No.-

Glucose oxidase (GOx) and horseradish peroxidase (HRP) based bienzymes are entrapped in apolyethylenimine (PEI) matrix and then immobilized onto a substrate consisting of carbon nanotube(CNT) and pyrene boronic acid (PBA) (CNT/PBA/[HRP/PEI/GOx]). This structure is considered as thecathodic catalyst for the glucose biofuel cell (GBFC). According to the performance evaluations of thecatalyst, the catalytic activity for the oxygen reduction reaction (ORR) is improved because of thebienzyme entrapped well in PEI, and also, because the CNT/PBA substrate promotes electron transfer bythe formation of p–p stacking and the reduction of the electron transfer pathway distance. The high ORRreaction rate (38.7 mA cm 2 in the injection of 5 mM glucose) is clear evidence of an excellent catalyst. Inaddition, when the catalyst is adopted for the operation of a membrane GBFC, a high-power density(77.9 2.3 mW cm 2) is achieved, as well as good storage stability (81% of its initial activity even after 4weeks) and a high glucose consumption rate (8.7 0.2% from its initial concentration during 7 operatinghours). Alternatively, when the catalyst is used for the membraneless GBFC operation, a relatively highpowerdensity of 18 mW cm 2 is also obtained.

A correlation of results measured by cyclic voltammogram and impedance spectroscopy in glucose oxidase based biocatalysts

Marcelinus Christwardana,정용진,권용재 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.11

A new biocatalyst consisting of glucose oxidase (GOx) and polyethylenimine (PEI) immobilized on carbon nanotube (CNT) (CNT/PEI/GOx) was developed, while cyclic voltammogram (CV) behaviors of several related catalysts including the CNT/PEI/GOx were analyzed in terms of charge transfer resistances (Rcts) obtained by measuring Nyquist plots using electrochemical impedance spectroscopy (EIS). A qualitative correlation between the flavin adenine dinucleotide (FAD) redox reactivity measured by the CV and Rct was established. As factors affecting both the FAD reactivity and Rct, concentrations of GOx, glucose, and phosphate buffer solution, electrolyte pH and ambient condition were considered and evaluations of the catalysts using the CV curves and Nyquist plots confirmed that a pattern in the FAD reactivity was closely linked to that in the Rct, implying that FAD reactivities of the catalysts are predicted by the measurements of their Rcts. Even regarding performance of the enzymatic biofeul cells (EBCs) using the reacted catalysts, a pattern of the Rcts is compatible with that in the maximum power densities (MPDs) of the EBCs.

Early-stage performance evaluation of flowing microbial fuel cells using chemically treated carbon felt and yeast biocatalyst

Christwardana, Marcelinus,Frattini, Domenico,Accardo, Grazia,Yoon, Sung Pil,Kwon, Yongchai Elsevier 2018 APPLIED ENERGY Vol.222 No.-

<P><B>Abstract</B></P> <P>The performance of closed-loop flowing-type microbial fuel cells using differently pretreated carbon felts is measured. Yeast cultivated from <I>S. cerevisiae</I> is used as biocatalyst, while glucose is the substrate. For the pretreatment of felt, acetone, nitric acid, and polyethyleneimine are employed. First the optimal conditions for yeast cultivation are quantitatively determined. As a result, a high yeast growth rate (1.083 h<SUP>−1</SUP>) and the optimal yeast growing time (48 h) for cell tests are obtained. The differently pretreated felts are analyzed by X-ray photoelectron spectroscopy, electrochemical impedance spectroscopy and optical microscopy. Conductivity, charge transfer resistance, and CdbndO and CsbndN groups dangled on the felt are crucial parameters determining the performance of the microbial fuel cell. Particularly, the conjugation effects of pi-pi bonds and lone pairs facilitating the attachment of yeast to the CdbndO and CsbndN groups on the carbon felt promote (i) mutual adhesion between them and (ii) growth of yeast on CF-PEI. This correlation is confirmed by optical analysis of the felts after the cell tests. To evaluate the early-stage performance of the microbial fuel cells using the different felts, polarization curves are measured. In the measurements, the maximum power density of the cells depends on the superficial state of felts, while the performance of the cell using the PEI-treated felt is best, at 256.3 ± 11.5 mW·m<SUP>−2</SUP>. These data match other results attained by pretreatments.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Yeast and chemically treated CF effects on MFC performance are investigated. </LI> <LI> CdbndO/CsbndN dangled on CF-PEI are key bonds for performance enhancement. </LI> <LI> Pi-pi bond conjugation and lone electron pair induce performance enhancement. </LI> <LI> High yeast growth rate and optimal yeast growing time are determined. </LI> <LI> MPD of MFC using CF-PEI is 256.3 mW m<SUP>2</SUP>. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Co-immobilization of glucose oxidase and catalase for enhancing the performance of a membraneless glucose biofuel cell operated under physiological conditions

Christwardana, Marcelinus,Chung, Yongjin,Kwon, Yongchai The Royal Society of Chemistry 2017 Nanoscale Vol.9 No.5

<P>Glucose oxidase (GOx)-catalase co-immobilized catalyst (CNT/PEI/(GOx-Cat)) was synthesized, and its catalytic activity and electrical performance were investigated and compared, whereas the amount of immobilized catalase was optochemically inspected by chemiluminescence (CL) assay. With the characterizations, it was confirmed that the catalase was well immobilized on the CNT/PEI surface, whereas both the GOx and catalase play their roles well in the catalyst. According to the measurements of the current density peak of the flavin adenine dinucleotide (FAD) redox reaction, electron transfer rate, Michaelis-Menten constants and sensitivity, CNT/PEI/(GOx-Cat) shows the best values, and this is attributed to the excellent catalytic activity of GOx and the H2O2 decomposition capability of the catalase. To evaluate the electrical performance, a membraneless glucose biofuel cell (GBFC) adopting the catalyst was operated under physiological conditions and produced a maximum power density (MPD) of 180.8 +/- 22.3 mu W cm(-2), which is the highest value compared to MPDs obtained by adoption of other catalysts. With such results, it was clarified that the CNT/PEI/(GOx-Cat) manufactured by co-immobilization of GOx and catalase leads to enhancements in the catalytic activity and GBFC performance due to the synergetic effects of (i) effective removal of harmful H2O2 moiety by catalase and (ii) superior activation of desirable reactions by GOx.</P>

Optimization of glucose concentration and glucose/yeast ratio in yeast microbial fuel cell using response surface methodology approach

Christwardana, Marcelinus,Frattini, Domenico,Accardo, Grazia,Yoon, Sung Pil,Kwon, Yongchai Elsevier 2018 Journal of Power Sources Vol.402 No.-

<P><B>Abstract</B></P> <P>In this work the influence of two practical parameters, i.e. glucose concentration and glucose/yeast ratio, on performance of yeast-based microbial fuel cells (yeast-MFC) is investigated. The novel carbon felt pretreated with polyethylenimine is adopted as anode in open-air single chamber yeast-MFCs. The combination of the two parameters is optimized using response surface methodology with statistical approach. The optional presence of methylene blue as mediator is also included for comparison. Experimental dataset is initially built as reference and 4 mathematical equations are derived to predict the response regarding open circuit voltage (OCV) and maximum power density (MPD). By varying glucose concentration and glucose/yeast ratio, computed response surfaces show different responses are obtained and an optimum point exists within the range investigated. Finally, the optimized combinations for yeast-MFCs with/without mediator are predicted and response is verified in real experiment. The model tends to slightly overestimate the response, but accuracy is within confident range for both OCV and MPD. In fact, MPD obtained for the optimized yeast-MFC without mediator is 340.9 mW m<SUP>−2</SUP>, 3.2% lower than model, while it is 374.4 mW m<SUP>−2</SUP>, 5% lower than model, for the case including mediator. The discrepancy of OCV prediction is below 3%, making the approach reliable.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Single chamber yeast microbial fuel cell with a novel anode is optimized. </LI> <LI> Response Surface Methodology was used to tune 2 operational parameters. </LI> <LI> Dataset of experimental response with or without methylene blue was created. </LI> <LI> The shape of response surface shows that a non-trivial optimum point exists. </LI> <LI> The optimal point was experimentally checked and error was only 3–5%. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

A hybrid biocatalyst consisting of silver nanoparticle and naphthalenethiol self-assembled monolayer prepared for anchoring glucose oxidase and its use for an enzymatic biofuel cell

Christwardana, Marcelinus,Kim, Do-Heyoung,Chung, Yongjin,Kwon, Yongchai Elsevier BV * North-Holland 2018 Applied Surface Science Vol.429 No.-

<P><B>Abstract</B></P> <P>A novel hybrid biocatalyst is synthesized by the enzyme composite consisting of silver nanoparticle (AgNP), naphthalene-thiol based couplers (Naph-SH) and glucose oxidase (GOx), which is then bonded with the supporter consisting of polyethyleneimine (PEI) and carbon nanotube (CNT) (CNT/PEI/AgNPs/Naph-SH/GOx) to facilitate glucose oxidation reaction (GOR). Here, the AgNPs play a role in obstructing denaturation of the GOx molecules from the supporter because of Ag-thiol bond, while the PEIs have the AgNPs keep their states without getting ionized by hydrogen peroxide produced during anodic reaction. The Naph-SHs also prevent ionization of the AgNP by forming self-assembled monolayer on their surface. Such roles of each component enable the catalyst to form (i) hydrophobic interaction between the GOx molecules and supporter and (ii) π-conjugated electron pathway between the GOx molecules and AgNP, promoting electron transfer. Catalytic nature of the catalyst is characterized by measuring catalytic activity and performance of enzymatic biofuel cell (EBC) using the catalyst. Regarding the catalytic activity, the catalyst leads to high electron transfer rate constant (9.6±0.4s<SUP>−1</SUP>), low Michaelis-Menten constant (0.51±0.04mM), and low charge transfer resistance (7.3Ωcm<SUP>2</SUP>) and high amount of immobilized GOx (54.6%), while regarding the EBC performance, high maximum power density (1.46±0.07mWcm<SUP>−2</SUP>) with superior long-term stability result are observed.</P> <P><B>Highlights</B></P> <P> <UL> <LI> CNT/PEI/AgNP/Naph-SH/GOx is suggested as anodic catalyst for the EBC. </LI> <LI> Catalytic activity and stability are enhanced due to AgNP and Naph-SH. </LI> <LI> Ag-thiol bonds obstruct denaturation of the GOx molecule. </LI> <LI> Naph-SH SAM promotes electron transfer and reduces charge transfer resistance. </LI> <LI> EBC including CNT/PEI/AgNP/Naph-SH/GOx shows high power density. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Glucose biofuel cells using the two-step reduction reaction of bienzyme structure as cathodic catalyst

Christwardana, Marcelinus,Chung, Yongjin,Kim, Do-Heyoung,Kwon, Yongchai Elsevier 2019 Journal of industrial and engineering chemistry Vol.71 No.-

<P><B>Abstract</B></P> <P>Glucose oxidase (GOx) and horseradish peroxidase (HRP) based bienzymes are entrapped in a polyethylenimine (PEI) matrix and then immobilized onto a substrate consisting of carbon nanotube (CNT) and pyrene boronic acid (PBA) (CNT/PBA/[HRP/PEI/GOx]). This structure is considered as the cathodic catalyst for the glucose biofuel cell (GBFC). According to the performance evaluations of the catalyst, the catalytic activity for the oxygen reduction reaction (ORR) is improved because of the bienzyme entrapped well in PEI, and also, because the CNT/PBA substrate promotes electron transfer by the formation of π–π stacking and the reduction of the electron transfer pathway distance. The high ORR reaction rate (38.7μAcm<SUP>−2</SUP> in the injection of 5mM glucose) is clear evidence of an excellent catalyst. In addition, when the catalyst is adopted for the operation of a membrane GBFC, a high-power density (77.9±2.3μWcm<SUP>−2</SUP>) is achieved, as well as good storage stability (81% of its initial activity even after 4 weeks) and a high glucose consumption rate (8.7±0.2% from its initial concentration during 7 operating hours). Alternatively, when the catalyst is used for the membraneless GBFC operation, a relatively high-power density of 18μWcm<SUP>−2</SUP> is also obtained.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We suggest CNT/PBA/[HRP/PEI/GOx] catalyst as cathodic catalyst of GBFC. </LI> <LI> Bienzyme structure consisting of GOx and HRP are used as the catalyst. </LI> <LI> ORR is improved because of bienzyme entrapped well in PEI. </LI> <LI> CNT/PBA promotes electron transfer due to π–π stacking and short pathway distance. </LI> <LI> GBFC containing CNT/PBA/[HRP/PEI/GOx] catalyst induces high performance. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Effects of the gold nanoparticles including different thiol functional groups on the performances of glucose-oxidase-based glucose sensing devices

Marcelinus Christwardana,정용진,Daniel Chris Tannia,Yongchai Kwon 한국화학공학회 2018 Korean Journal of Chemical Engineering Vol.35 No.12

Thiol-based self-assembled anchor linked to glucose oxidase (GOx) and gold nanoparticle (GNP) cluster is suggested to enhance the performance of glucose biosensor. By the adoption of thiol-based anchors, the activity of biocatalyst consisting of GOx, GNP, polyethyleneimine (PEI) and carbon nanotube (CNT) is improved because they play a crucial role in preventing the leaching out of GOx. They also promote electron collection and transfer, and this is due to a strong hydrophobic interaction between the active site of GOx and the aromatic ring of anchor, while the effect is optimized with the use of thiophenol anchor due to its simple configuration. Based on that, it is quantified that by the adoption of thiophenol as anchor, the current density of flavin adenine dinucleotide (FAD) redox reaction increases about 42%, electron transfer rate constant (ks) is 9.1±0.1 s1 and the value is 26% higher than that of catalyst that does not use the anchor structure.