Real-Time Sensing of Hydrogen Peroxide by ITO/MWCNT/Horseradish Peroxidase Enzyme Electrode

<div>The emission spectra of tetraguaiacol produced by the enzyme reaction of f-<svg height="12.0836pt" id="M48" style="vertical-align:-0.2455997pt" version="1.1" viewbox="-0.0498162 -11.838 78.4661 12.0836" width="78.4661pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M861 0V28C774 35 771 41 768 147L759 509C756 612 762 614 851 622V650H681L449 149L221 650H57V622C148 613 153 609 144 479L130 271C123 166 117 123 111 88C104 46 85 34 26 28V0H259V28C192 35 169 42 167 90C166 130 166 173 170 256L185 541H187L411 7H431L675 555H679L683 147C683 41 680 35 598 28V0H861Z" id="g121-75"></path><glyph.data ascent="989" descent="-360" horiz-adv-x="891" vert-adv-y="891"></glyph.data></g><g transform="matrix(.013,0,0,-0.013,11.466,0)"><path d="M614 175C564 76 510 21 408 21C256 21 146 149 146 336C146 488 235 629 402 629C510 629 570 586 597 480L626 488C620 541 614 582 606 638C578 643 510 665 429 665C206 665 44 527 44 316C44 157 153 -15 402 -15C474 -15 558 5 586 11C604 45 629 119 643 165L614 175Z" id="g121-65"></path><glyph.data ascent="989" descent="-360" horiz-adv-x="665" vert-adv-y="665"></glyph.data></g><g transform="matrix(.013,0,0,-0.013,20.111,0)"><path d="M956 650H736V622C814 613 818 602 804 542C789 471 733 275 691 141H689C628 314 570 476 514 641H485C434 478 377 312 323 142H321C277 284 238 419 199 554C184 605 186 613 259 622V650H16V622C77 615 92 606 117 524C172 346 228 170 281 -11H312C363 151 419 312 475 488H477C528 343 597 150 652 -11H683C765 269 826 458 848 522C878 605 887 613 956 622V650Z" id="g121-85"></path><glyph.data ascent="989" descent="-360" horiz-adv-x="971" vert-adv-y="971"></glyph.data></g><g transform="matrix(.013,0,0,-0.013,32.734,0)"><path d="M719 650H483V622C553 619 576 606 581 560C585 532 588 487 588 394V148H585L167 650H20V622C67 618 88 610 109 585C127 562 129 557 129 484V264C129 173 126 124 123 93C118 44 92 31 35 28V0H272V28C204 32 181 44 176 95C173 124 170 172 170 264V515H172L598 -9H629V394C629 487 631 532 635 563C639 606 663 619 719 622V650Z" id="g121-76"></path><glyph.data ascent="989" descent="-360" horiz-adv-x="743" vert-adv-y="743"></glyph.data></g><g transform="matrix(.013,0,0,-0.013,42.393,0)"><path d="M592 498C586 556 582 629 581 675H560C545 656 537 650 510 650H115C87 650 74 652 60 675H40C38 620 33 555 28 495H57C69 539 77 568 89 585C102 607 122 616 205 616H267V123C267 44 259 34 168 28V0H454V28C360 34 352 44 352 123V616H422C498 616 514 608 531 584C542 568 552 543 562 495L592 498Z" id="g121-82"></path><glyph.data ascent="989" descent="-360" horiz-adv-x="617" vert-adv-y="617"></glyph.data></g><g transform="matrix(.0091,0,0,-0.0091,50.603,-5.741)"><path d="M618 181C565 77 513 26 413 26C264 26 151 150 151 336C151 486 240 625 407 625C516 625 573 582 600 475L634 483C627 540 622 581 613 638C585 643 518 665 435 665C211 665 46 526 46 315C46 158 157 -15 406 -15C480 -15 564 4 594 12C612 43 638 121 651 168L618 181Z" id="g58-65"></path><glyph.data ascent="1007" descent="-369" horiz-adv-x="673" vert-adv-y="673"></glyph.data></g><g transform="matrix(.0091,0,0,-0.0091,56.81,-5.741)"><path d="M387 665C175 665 46 498 46 318C46 123 194 -15 374 -15C558 -15 712 114 712 333C712 535 557 665 387 665ZM364 625C495 625 607 518 607 306C607 115 505 25 396 25C256 25 151 161 151 346C151 532 255 625 364 625Z" id="g58-77"></path><glyph.data ascent="1007" descent="-369" horiz-adv-x="757" vert-adv-y="757"></glyph.data></g><g transform="matrix(.0091,0,0,-0.0091,63.872,-5.741)"><path d="M387 665C175 665 46 498 46 318C46 123 194 -15 374 -15C558 -15 712 114 712 333C712 535 557 665 387 665ZM364 625C495 625 607 518 607 306C607 115 505 25 396 25C256 25 151 161 151 346C151 532 255 625 364 625Z" id="g58-77"></path><glyph.data ascent="1007" descent="-369" horiz-adv-x="757" vert-adv-y="757"></glyph.data></g><g transform="matrix(.0091,0,0,-0.0091,70.696,-5.741)"><path d="M738 650H471V617C551 612 559 606 559 524V368H218V524C218 606 227 612 305 617V650H38V617C123 612 131 606 131 524V126C131 44 124 38 41 33V0H310V33C226 38 218 44 218 126V321H559V126C559 44 551 38 463 33V0H737V33C654 38 646 44 646 126V524C646 606 654 612 738 617V650Z" id="g58-70"></path><glyph.data ascent="1007" descent="-369" horiz-adv-x="777" vert-adv-y="777"></glyph.data></g></svg>/HRP complex before (guaiacol) and after the reaction at different HRP incubation concentrations (as indicated) and the carboxyl-functionalized MWCNT as a reference. Measurement was done as described in Materials and Methods.</div>

Journal of Nanomaterials

fig7

Figure 7

Figure 7: Real-Time Sensing of Hydrogen Peroxide by ITO/MWCNT/Horseradish Peroxidase Enzyme Electrode 