# US 2026/0092889 A1 · Lactic acid detection electrode and method for producing the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2026/0092889 A1 - Document ID: US20260092889A1 - Status: Published application - Kind: A1 - Application number: 18/987,306 - Filed: 2024-12-19 - Published: 2026-04-02 - Earliest claimed: 2024-09-30 - Assignees: National Taiwan Normal University - Applicants: National Taiwan Normal University - Inventors: TIEN-LI CHANG; QI-XUAN WU; SONG-PU HUANG; YUAN-JUN CHEN - Web page: https://patentgrep.com/patent/US20260092889A1 ## CPC - G01N 27/3278: {involving nanosized elements, e.g. nanogaps or nanoparticles (nanopores G01N33/48721; magnetic beads G01N27/745)} - G01N 27/4145: {specially adapted for biomolecules, e.g. gate electrode with immobilised receptors} - G01N 27/4146: {involving nanosized elements, e.g. nanotubes, nanowires} - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract A lactic acid detection electrode and a method for producing the lactic acid detection electrode are provided. The lactic acid detection electrode includes a substrate and an electrode pattern formed on the substrate. A surface of the electrode pattern has a surface modification structure, and the surface modification structure has a p-n heterojunction formed between p-type reduced graphene oxide and n-type metal oxide. The electrode pattern includes a first electrode and a second electrode. The first electrode has a first spiral line. The second electrode has a second spiral line. The first spiral line and the second spiral line respectively extend toward each other along a spiral path, and are spirally wound around each other without contacting each other. ## Claims ### Claim 1 A lactic acid detection electrode, comprising: a substrate; and an electrode pattern formed on the substrate, the electrode pattern at least partially exposing a surface of the substrate; wherein the surface of the electrode pattern has a surface modification structure, and the surface modification structure has a p-n heterojunction that is formed between a reduced graphene oxide and a metal oxide, and wherein a conductivity type of the reduced graphene oxide is p-type, and a conductivity type of the metal oxide is n-type; wherein the electrode pattern includes at least: a first electrode having a first spiral line; and a second electrode having a second spiral line; wherein the first spiral line and the second spiral line respectively extend toward each other along a spiral path, and the first spiral line and the second spiral line are spirally wound around each other and spaced apart without contacting each other. ### Claim 2 (depends on 1) The lactic acid detection electrode according to claim 1, wherein a first spiral sidewall of the first spiral line is formed with a plurality of first electrode fingers arranged along the spiral path and spaced apart from each other, a second spiral sidewall of the second spiral line facing toward the first spiral line is formed with a plurality of second electrode fingers arranged along the spiral path and spaced apart from each other; wherein the plurality of first electrode fingers and the plurality of second electrode fingers are interdigitated with each other without contacting each other. ### Claim 3 (depends on 2) The lactic acid detection electrode according to claim 2, wherein, in the electrode pattern, an interdigitated spacing is defined between each of the first electrode fingers and an adjacent one of the second electrode fingers; wherein the interdigitated spacing is between 0.2 mm and 1.8 mm. ### Claim 4 (depends on 1) The lactic acid detection electrode according to claim 1, wherein the surface modification structure of the electrode pattern has a dual-phase crystal structure including an anatase phase and a rutile phase, and further has a structure mixed with the reduced graphene oxide. ### Claim 5 (depends on 1) The lactic acid detection electrode according to claim 1, wherein the substrate is a flexible polymer substrate, and the metal oxide is titanium dioxide. ### Claim 6 A method for producing a lactic acid detection electrode, comprising: a film layer formation step, which includes forming a composite material film layer on a substrate, the composite material film layer containing a graphene oxide (GO) and a metal oxide; a surface modification step, which includes performing a first laser process on a surface of the composite material film layer using an ultrafast laser to form a surface modification structure on the substrate; wherein the surface modification structure has a p-n heterojunction formed between a reduced graphene oxide reduced from the graphene oxide and the metal oxide, and wherein a conductivity type of the reduced graphene oxide is p-type, and a conductivity type of the metal oxide is n-type; and a pattern formation step, which includes performing a second laser process using the ultrafast laser to at least partially cut and remove the surface modification structure to partially expose the substrate, thereby forming an electrode pattern, wherein a surface of the electrode pattern has the surface modification structure; wherein the electrode pattern at least includes a first electrode and a second electrode, the first electrode has a first spiral line, and the second electrode has a second spiral line; wherein the first spiral line and the second spiral line respectively extend toward each other along a spiral path, and the first spiral line and the second spiral line are spirally wound around each other and spaced apart without contacting each other. ### Claim 7 (depends on 6) The method according to claim 6, wherein, in the film layer formation step, the metal oxide in the composite material film layer has a first crystal phase, and the first crystal phase is an anatase phase. ### Claim 8 (depends on 7) The method according to claim 7, wherein, in the surface modification step, the ultrafast laser induces the metal oxide in the composite material film layer to be at least partially transformed from the first crystal phase to a second crystal phase, and reduces the graphene oxide to the reduced graphene oxide (rGO); and wherein the second crystal phase is a rutile phase. ### Claim 9 (depends on 6) The method according to claim 6, wherein, in the film layer formation step, the graphene oxide in the composite material film layer is formed on the substrate as a continuous lamellar structure, and the metal oxide is dispersed in granular form on the graphene oxide. ### Claim 10 (depends on 6) The method according to claim 6, wherein a laser energy density in the pattern formation step is greater than a laser energy density in the surface modification step.