659862d1f7205d373e111d5eca5528ba chemosensors-13-00211-v2.pdf a842b82694f75d82c86f2bb17f6b7d5c8ff435c9 chemosensors-13-00211-v2.pdf b3e573459dce124e2f0fef338885e34d2161ae33099c833f0c26a4117277187a chemosensors-13-00211-v2.pdf Title: Electrochemical Assessment of Microbial Activity Using PEDOT:PSS-Immobilized Cells Subject: This study presents a microbial sensing device that employs a poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) matrix to immobilize viable and metabolically Escherichia coli cells. This device enables the monitoring of microorganism metabolic activity in response to external stimuli such as variations in carbon sources or exposure to inhibitory or toxic compounds. PEDOT:PSS, a conductive and chemically stable polymer, was electrodeposited onto screen-printed electrodes, successfully entrapping approximately 1.26 107 cells per electrode. The confocal microscopy of Live/Dead-stained samples confirmed a uniform cell distribution and an average viability of ~78%. Ferricyanide respirometry validated the metabolic activity of the immobilized cells. The biosensor’s performance was evaluated using 3,5-dichlorophenol (3,5-DCP) as a reference toxicant. The observed inhibition of microbial activity correlated with 3,5-DCP concentration, yielding a half-maximal effective concentration (EC50) of 9 ppm, consistent with the literature values. Keywords: PEDOT:PSS; cell immobilization; Escherichia coli; metabolic activity; microbial activity; ferricyanide respirometry; toxicity assessment Author: N. Vigués, C. Cantallops-Vilà and J. Mas Creator: LaTeX with hyperref Producer: pdfTeX-1.40.25 CreationDate: Wed Jun 11 08:58:02 2025 CEST ModDate: Wed Jun 11 08:59:53 2025 CEST Custom Metadata: no Metadata Stream: no Tagged: no UserProperties: no Suspects: no Form: none JavaScript: no Pages: 10 Encrypted: no Page size: 595.276 x 841.89 pts (A4) Page rot: 0 File size: 1402037 bytes Optimized: no PDF version: 1.7 name type encoding emb sub uni object ID ------------------------------------ ----------------- ---------------- --- --- --- --------- WNWTFR+VnURWPalladioL-Bold Type 1 Custom yes yes yes 10 0 VVMMDR+URWPalladioL-Roma Type 1 Custom yes yes yes 16 0 MMKSJC+URWPalladioL-Bold Type 1 Custom yes yes yes 22 0 SVWEZP+URWPalladioL-Ital Type 1 Custom yes yes yes 27 0 UWJUYN+CMSY10 Type 1 Builtin yes yes yes 32 0 OLYXNT+VnURWPalladioL Type 1 Custom yes yes yes 37 0 OVNEXW+EURM10 Type 1 Builtin yes yes yes 66 0 JHYTSG+CMR10 Type 1 Builtin yes yes yes 74 0 KKOPBI+PalatinoLinotype-Bold CID TrueType Identity-H yes yes yes 84 0 KKPACM+Arial-BoldMT TrueType WinAnsi yes yes no 90 0 KKPACO+ArialMT TrueType WinAnsi yes yes no 93 0 KKPACP+SymbolMT CID TrueType Identity-H yes yes yes 96 0 KKOPCI+PalatinoLinotype-Roman CID TrueType Identity-H yes yes yes 102 0 KKOPCJ+PalatinoLinotype-Italic CID TrueType Identity-H yes yes yes 108 0 KKOPBI+PalatinoLinotype-Bold CID TrueType Identity-H yes yes yes 122 0 KKPACM+Arial-BoldMT TrueType WinAnsi yes yes no 128 0 KKPACP+SymbolMT CID TrueType Identity-H yes yes yes 131 0 KKOPCI+PalatinoLinotype-Roman CID TrueType Identity-H yes yes yes 137 0 KKOPCJ+PalatinoLinotype-Italic CID TrueType Identity-H yes yes yes 143 0 KKOPBI+PalatinoLinotype-Bold CID TrueType Identity-H yes yes yes 157 0 KKOPCI+PalatinoLinotype-Roman CID TrueType Identity-H yes yes yes 163 0 KKOPCJ+PalatinoLinotype-Italic CID TrueType Identity-H yes yes yes 169 0 KKOPBI+PalatinoLinotype-Bold CID TrueType Identity-H yes yes yes 183 0 KKOPCI+PalatinoLinotype-Roman CID TrueType Identity-H yes yes yes 189 0 KKOPCJ+PalatinoLinotype-Italic CID TrueType Identity-H yes yes yes 195 0 KKOPBI+PalatinoLinotype-Bold CID TrueType Identity-H yes yes yes 212 0 KKPACM+Arial-BoldMT TrueType WinAnsi yes yes no 218 0 KKPACO+ArialMT TrueType WinAnsi yes yes no 221 0 KKOPCI+PalatinoLinotype-Roman CID TrueType Identity-H yes yes yes 224 0 KKOPCJ+PalatinoLinotype-Italic CID TrueType Identity-H yes yes yes 230 0 KKOPBI+PalatinoLinotype-Bold CID TrueType Identity-H yes yes yes 241 0 KKPACM+Arial-BoldMT TrueType WinAnsi yes yes no 247 0 KKPACO+ArialMT TrueType WinAnsi yes yes no 250 0 KKPACP+SymbolMT CID TrueType Identity-H yes yes yes 253 0 KKPBGK+Arial-ItalicMT TrueType WinAnsi yes yes no 259 0 KKOPCI+PalatinoLinotype-Roman CID TrueType Identity-H yes yes yes 262 0 KKOPCJ+PalatinoLinotype-Italic CID TrueType Identity-H yes yes yes 268 0 Jhove (Rel. 1.28.0, 2023-05-18) Date: 2025-07-09 02:10:10 CEST RepresentationInformation: chemosensors-13-00211-v2.pdf ReportingModule: PDF-hul, Rel. 1.12.4 (2023-03-16) LastModified: 2025-07-08 13:16:18 CEST Size: 1402037 Format: PDF Version: 1.7 Status: Well-Formed and valid SignatureMatches: PDF-hul MIMEtype: application/pdf PDFMetadata: Objects: 385 FreeObjects: 1 IncrementalUpdates: 0 DocumentCatalog: PageLayout: SinglePage PageMode: UseNone Outlines: Item: Title: Introduction Destination: section.1 Item: Title: Materials and Methods Destination: section.2 Children: Item: Title: Chemicals and Materials Destination: subsection.2.1 Item: Title: Microorganisms Destination: subsection.2.2 Item: Title: PEDOT:PSS Biosensor Fabrication Destination: subsection.2.3 Item: Title: Biosensor Characterization Destination: subsection.2.4 Children: Item: Title: Confocal Imaging and Profilometry Destination: subsubsection.2.4.1 Item: Title: Ferricyanide Respirometry Destination: subsubsection.2.4.2 Item: Title: Toxicity Assay Destination: subsubsection.2.4.3 Item: Title: Results and Discussion Destination: section.3 Item: Title: Conclusions Destination: section.4 Item: Title: References Destination: section.5 Info: Title: Electrochemical Assessment of Microbial Activity Using PEDOT:PSS-Immobilized Cells Author: N. Vigués, C. Cantallops-Vilà and J. Mas Subject: This study presents a microbial sensing device that employs a poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) matrix to immobilize viable and metabolically Escherichia coli cells. This device enables the monitoring of microorganism metabolic activity in response to external stimuli such as variations in carbon sources or exposure to inhibitory or toxic compounds. PEDOT:PSS, a conductive and chemically stable polymer, was electrodeposited onto screen-printed electrodes, successfully entrapping approximately 1.26 107 cells per electrode. The confocal microscopy of Live/Dead-stained samples confirmed a uniform cell distribution and an average viability of ~78%. Ferricyanide respirometry validated the metabolic activity of the immobilized cells. The biosensor’s performance was evaluated using 3,5-dichlorophenol (3,5-DCP) as a reference toxicant. The observed inhibition of microbial activity correlated with 3,5-DCP concentration, yielding a half-maximal effective concentration (EC50) of 9 ppm, consistent with the literature values. Keywords: PEDOT:PSS; cell immobilization; Escherichia coli; metabolic activity; microbial activity; ferricyanide respirometry; toxicity assessment Creator: LaTeX with hyperref Producer: pdfTeX-1.40.25 CreationDate: Wed Jun 11 08:58:02 CEST 2025 ModDate: Wed Jun 11 08:59:53 CEST 2025 ID: 0x05125f069a126fcc504b905aa7d768c7, 0x05125f069a126fcc504b905aa7d768c7 Filters: FilterPipeline: FlateDecode Fonts: Type1: Font: BaseFont: VVMMDR+URWPalladioL-Roma FontSubset: true FirstChar: 2 LastChar: 241 FontDescriptor: FontName: VVMMDR+URWPalladioL-Roma Flags: Symbolic FontBBox: -166, -283, 1021, 943 FontFile: true EncodingDictionary: Differences: true ToUnicode: true Font: BaseFont: UWJUYN+CMSY10 FontSubset: true FirstChar: 0 LastChar: 21 FontDescriptor: FontName: UWJUYN+CMSY10 Flags: Symbolic FontBBox: -29, -960, 1116, 775 FontFile: true ToUnicode: true Font: BaseFont: OVNEXW+EURM10 FontSubset: true FirstChar: 22 LastChar: 22 FontDescriptor: FontName: OVNEXW+EURM10 Flags: Symbolic FontBBox: -32, -243, 1060, 720 FontFile: true ToUnicode: true Font: BaseFont: OLYXNT+VnURWPalladioL FontSubset: true FirstChar: 160 LastChar: 225 FontDescriptor: FontName: OLYXNT+VnURWPalladioL Flags: Symbolic FontBBox: -166, -283, 1021, 943 FontFile: true EncodingDictionary: Differences: true ToUnicode: true Font: BaseFont: MMKSJC+URWPalladioL-Bold FontSubset: true FirstChar: 3 LastChar: 233 FontDescriptor: FontName: MMKSJC+URWPalladioL-Bold Flags: Symbolic FontBBox: -152, -301, 1000, 935 FontFile: true EncodingDictionary: Differences: true ToUnicode: true Font: BaseFont: WNWTFR+VnURWPalladioL-Bold FontSubset: true FirstChar: 160 LastChar: 160 FontDescriptor: FontName: WNWTFR+VnURWPalladioL-Bold Flags: Symbolic FontBBox: -152, -301, 1000, 935 FontFile: true EncodingDictionary: Differences: true ToUnicode: true Font: BaseFont: JHYTSG+CMR10 FontSubset: true FirstChar: 61 LastChar: 61 FontDescriptor: FontName: JHYTSG+CMR10 Flags: Symbolic FontBBox: -40, -250, 1009, 750 FontFile: true ToUnicode: true Font: BaseFont: SVWEZP+URWPalladioL-Ital FontSubset: true FirstChar: 45 LastChar: 122 FontDescriptor: FontName: SVWEZP+URWPalladioL-Ital Flags: Symbolic FontBBox: -170, -305, 1010, 941 FontFile: true EncodingDictionary: Differences: true ToUnicode: true Pages: Page: Sequence: 1 Annotations: Annotation: Subtype: Link Rect: 34, 177, 152, 186 Annotation: Subtype: Link Rect: 34, 167, 107, 174 Annotation: Subtype: Link Rect: 36, 75, 152, 84 Annotation: Subtype: Link Rect: 34, 63, 89, 72 Annotation: Subtype: Link Rect: 34, 773, 177, 809 Annotation: Subtype: Link Rect: 515, 773, 560, 809 Annotation: Subtype: Link Rect: 195, 663, 206, 677 Annotation: Subtype: Link Rect: 261, 663, 272, 677 Annotation: Subtype: Link Rect: 296, 284, 303, 293 ActionDest: 277 Annotation: Subtype: Link Rect: 306, 284, 313, 293 ActionDest: 277 Annotation: Subtype: Link Rect: 250, 186, 257, 195 ActionDest: 277 Annotation: Subtype: Link Rect: 304, 158, 311, 167 ActionDest: 277 Annotation: Subtype: Link Rect: 430, 130, 437, 139 ActionDest: 277 Annotation: Subtype: Link Rect: 473, 117, 480, 126 ActionDest: 277 Annotation: Subtype: Link Rect: 480, 116, 487, 126 ActionDest: 277 Annotation: Subtype: Link Rect: 439, 103, 446, 112 ActionDest: 277 Annotation: Subtype: Link Rect: 447, 103, 458, 112 ActionDest: 277 Annotation: Subtype: Link Rect: 196, 89, 208, 98 ActionDest: 277 Annotation: Subtype: Link Rect: 253, 89, 265, 98 ActionDest: 277 Annotation: Subtype: Link Rect: 331, 89, 343, 98 ActionDest: 277 Annotation: Subtype: Link Rect: 386, 27, 560, 37 Annotation: Subtype: Link Rect: 34, 304, 87, 323 Page: Sequence: 2 Annotations: Annotation: Subtype: Link Rect: 331, 731, 343, 740 ActionDest: 277 Annotation: Subtype: Link Rect: 359, 717, 371, 726 ActionDest: 277 Annotation: Subtype: Link Rect: 282, 689, 294, 698 ActionDest: 277 Annotation: Subtype: Link Rect: 294, 689, 306, 698 ActionDest: 277 Annotation: Subtype: Link Rect: 182, 675, 194, 684 ActionDest: 277 Annotation: Subtype: Link Rect: 321, 619, 333, 628 ActionDest: 277 Annotation: Subtype: Link Rect: 374, 577, 386, 586 ActionDest: 277 Annotation: Subtype: Link Rect: 389, 577, 401, 586 ActionDest: 277 Annotation: Subtype: Link Rect: 313, 564, 325, 572 ActionDest: 277 Annotation: Subtype: Link Rect: 325, 564, 337, 572 ActionDest: 277 Annotation: Subtype: Link Rect: 487, 549, 499, 559 ActionDest: 277 Annotation: Subtype: Link Rect: 499, 549, 511, 559 ActionDest: 277 Annotation: Subtype: Link Rect: 198, 86, 210, 96 ActionDest: 277 Page: Sequence: 3 Annotations: Annotation: Subtype: Link Rect: 280, 548, 292, 557 ActionDest: 277 Annotation: Subtype: Link Rect: 215, 132, 227, 141 ActionDest: 277 Page: Sequence: 4 Annotations: Annotation: Subtype: Link Rect: 337, 375, 344, 387 ActionDest: 71 Annotation: Subtype: Link Rect: 379, 68, 392, 80 ActionDest: 63 Page: Sequence: 5 Annotations: Annotation: Subtype: Link Rect: 532, 714, 539, 726 ActionDest: 114 Annotation: Subtype: Link Rect: 496, 658, 503, 670 ActionDest: 149 Annotation: Subtype: Link Rect: 237, 575, 244, 587 ActionDest: 114 Annotation: Subtype: Link Rect: 521, 260, 528, 272 ActionDest: 149 Annotation: Subtype: Link Rect: 477, 235, 489, 244 ActionDest: 277 Annotation: Subtype: Link Rect: 207, 121, 214, 133 ActionDest: 204 Page: Sequence: 6 Page: Sequence: 7 Annotations: Annotation: Subtype: Link Rect: 305, 758, 312, 767 ActionDest: 277 Annotation: Subtype: Link Rect: 313, 758, 325, 767 ActionDest: 277 Annotation: Subtype: Link Rect: 362, 359, 369, 371 ActionDest: 204 Annotation: Subtype: Link Rect: 361, 320, 368, 329 ActionDest: 277 Annotation: Subtype: Link Rect: 368, 320, 380, 329 ActionDest: 277 Annotation: Subtype: Link Rect: 381, 320, 393, 329 ActionDest: 280 Annotation: Subtype: Link Rect: 396, 320, 408, 329 ActionDest: 280 Page: Sequence: 8 Page: Sequence: 9 Annotations: Annotation: Subtype: Link Rect: 358, 663, 395, 674 Annotation: Subtype: Link Rect: 401, 663, 437, 674 Annotation: Subtype: Link Rect: 460, 651, 498, 661 Annotation: Subtype: Link Rect: 504, 651, 540, 661 Annotation: Subtype: Link Rect: 59, 612, 96, 622 Annotation: Subtype: Link Rect: 422, 586, 460, 597 Annotation: Subtype: Link Rect: 349, 561, 387, 571 Annotation: Subtype: Link Rect: 454, 548, 490, 559 Annotation: Subtype: Link Rect: 171, 510, 209, 520 Annotation: Subtype: Link Rect: 216, 471, 254, 482 Annotation: Subtype: Link Rect: 456, 446, 494, 457 Annotation: Subtype: Link Rect: 298, 420, 336, 431 Annotation: Subtype: Link Rect: 342, 420, 378, 431 Annotation: Subtype: Link Rect: 369, 394, 407, 405 Annotation: Subtype: Link Rect: 413, 394, 449, 405 Annotation: Subtype: Link Rect: 258, 369, 296, 380 Annotation: Subtype: Link Rect: 59, 344, 96, 354 Annotation: Subtype: Link Rect: 270, 318, 308, 329 Annotation: Subtype: Link Rect: 400, 292, 438, 303 Annotation: Subtype: Link Rect: 436, 267, 474, 278 Annotation: Subtype: Link Rect: 226, 242, 264, 252 Annotation: Subtype: Link Rect: 104, 217, 141, 227 Annotation: Subtype: Link Rect: 77, 191, 114, 201 Annotation: Subtype: Link Rect: 120, 191, 156, 201 Annotation: Subtype: Link Rect: 193, 166, 230, 176 Annotation: Subtype: Link Rect: 465, 152, 503, 163 Annotation: Subtype: Link Rect: 370, 126, 407, 137 Annotation: Subtype: Link Rect: 461, 101, 499, 112 Annotation: Subtype: Link Rect: 403, 75, 440, 86 Annotation: Subtype: Link Rect: 446, 75, 482, 86 Page: Sequence: 10 Annotations: Annotation: Subtype: Link Rect: 184, 744, 221, 754 Annotation: Subtype: Link Rect: 135, 719, 173, 729 Annotation: Subtype: Link Rect: 302, 692, 340, 703 Annotation: Subtype: Link Rect: 465, 667, 503, 678 Checksum: f245bd6f Type: CRC32 Checksum: 659862d1f7205d373e111d5eca5528ba Type: MD5 Checksum: a842b82694f75d82c86f2bb17f6b7d5c8ff435c9 Type: SHA-1 Checksum: b3e573459dce124e2f0fef338885e34d2161ae33099c833f0c26a4117277187a Type: SHA-256