▎ 摘　　要

NOVELTY - Sample pad comprises two inert filter layers and a graphene oxide layer, where the graphene oxide layer is stacked between the two inert filter layers. USE - The sample pad is useful for performing lateral flow assay i.e. lateral flow immunoassay for detecting analyte comprising medicament or medicament residue in body fluid. The body fluid is chosen from breast milk, blood, plasma, saliva, and urine, preferably breast milk. The medicament or medicament residue is chosen from carbamazepine (CBZ), caffeine (CAF), cholesterol, diclofenac (DCF), isolithocholic acid (ILA), creatinine, cotinine, atenolol, bisoprolol, metoprolol, carvedilol, celiprolol, esmolol, labetalol, levobunolol, metipranolol, diazepam, dihydrocodeine, doxepin, ibuprofen, methadone, metoprolol, morphine, diazepam, oxazepam, primidone, gentamicin, sotalol, tonalid, cocaine, benzoylecgonine, tetrahydrocannabinol, 3,4-methylenedioxymethamphetamine, herbicide (glyphosate, atrazine or metolachlor), pesticide (carbofuran or carbaryl), imidacloprid, fenitrothion, clenbuterol, a phthalate ester, a poly or perfluorinated alkyl substance (PFAS), a bisphenol, an antibiotic analog of penicillin, sulfonamide, tetracycline analog, fluoroquinolone analog, fluoroquinolone, macrolide analog, macrolide, beta -lactam, florfenicol, chloramphenicol and lincomycin (all claimed). ADVANTAGE - The sample pad detects diclofenac with lower limit of 0.08 mu g/l in a simple, sensitive, rapid and cost-effective manner. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) use of sample pad comprising a graphene oxide layer for depletion of fat and/or protein from a sample of a body fluid; (2) a lateral flow immunoassay for detecting an analyte comprising a medicament and/or a medicament residue in a physiological fluid involves filtering the sample through a graphene oxide layer, where graphene oxide layer is arranged with the sample pad of a lateral flow assay strip; (3) a lateral flow immunoassay device comprising the sample pad; and (4) a method for detecting a residue of a medicament in a body fluid involves (a) taking a sample of the body fluid with a polymer sponge by soaking the polymer sponge with the body fluid, where polymer sponge is treated in a 0.01 M EDTA, 0.05% Triton X-100 (RTM: t-Octylphenoxypolyethoxyethanol), 0.01% sodium azide and 0.05% Tween 20 (RTM: Polysorbate 20) and 25 mM borate buffer solution and dried, (b) filtering the recorded sample through a graphene oxide layer, which comprises a graphene oxide film ('super paper') or a single-layer graphene oxide flake, (c) performing a lateral flow immunoassay with 50 mu l collected and filtered sample, and (d) determining an amount of medicament residue in the sample using a calibration curve.