Label-Free Fluorescent Determination of Sunset Yellow in Soft Drinks Based on an Indicator-Displacement Assay

<div>Fluorescence intensity of 20 <i>μ</i>M luteolin (a), 20 <i>μ</i>M EGCG (c), and 20 <i>μ</i>M SY (e) versus CB7 concentration and plots of <svg height="12.5794pt" id="M17" style="vertical-align:-3.29107pt" version="1.1" viewbox="-0.0498162 -9.28833 53.9179 12.5794" width="53.9179pt" 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="M384 0V27C293 34 287 42 287 114V635C232 613 172 594 109 583V559L157 557C201 555 205 550 205 499V114C205 42 199 34 109 27V0H384Z" id="g113-50"></path></g><g transform="matrix(.013,0,0,-0.013,6.24,0)"><path d="M368 703H309L44 -163H104L368 703Z" id="g113-48"></path></g><g transform="matrix(.013,0,0,-0.013,11.601,0)"><path d="M300 -147C201 -63 143 98 143 270S200 602 300 686L282 710C136 610 70 450 70 271V270C70 89 136 -72 282 -170L300 -147Z" id="g113-41"></path></g><g transform="matrix(.013,0,0,-0.013,16.099,0)"><path d="M584 650H137L131 622C214 614 217 612 200 521L125 127C109 41 101 35 23 28L17 0H288L294 28C201 35 193 42 209 128L242 309H348C440 309 442 300 443 226H471L510 422H482C452 354 449 348 357 348H251L295 575C302 609 304 615 338 615H426C502 615 517 604 526 581C534 560 536 524 537 492L565 494C574 554 583 631 584 650Z" id="g113-71"></path></g><g transform="matrix(.0091,0,0,-0.0091,22.885,3.132)"><path d="M245 635C92 635 37 457 37 312C37 149 91 -12 244 -12C395 -12 449 166 449 312C449 469 395 635 245 635ZM243 598C332 598 358 454 358 312C358 173 334 26 245 26C158 26 128 174 128 313S152 598 243 598Z" id="g50-49"></path></g><g transform="matrix(.013,0,0,-0.013,30.737,0)"><path d="M535 230V280H52V230H535Z" id="g117-33"></path></g><g transform="matrix(.013,0,0,-0.013,41.274,0)"><path d="M584 650H137L131 622C214 614 217 612 200 521L125 127C109 41 101 35 23 28L17 0H288L294 28C201 35 193 42 209 128L242 309H348C440 309 442 300 443 226H471L510 422H482C452 354 449 348 357 348H251L295 575C302 609 304 615 338 615H426C502 615 517 604 526 581C534 560 536 524 537 492L565 494C574 554 583 631 584 650Z" id="g113-71"></path></g><g transform="matrix(.013,0,0,-0.013,49.169,0)"><path d="M275 270C275 450 212 609 64 710L45 686C145 604 203 442 203 270S147 -63 45 -147L64 -170C213 -68 275 89 275 270Z" id="g113-42"></path></g></svg> versus 1/[CB7] for luteolin (b), EGCG (d), and SY (f) (<i>λ</i>ex = 285 used for luteolin; <i>λ</i>ex = 260 nm used for EGCG; <i>λ</i>ex = 282 nm used for SY).</div>

Journal of Food Quality

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Figure 4

Figure 4: Label-Free Fluorescent Determination of Sunset Yellow in Soft Drinks Based on an Indicator-Displacement Assay 