Nanolayer deposition(s) of Ag and AgC composite on a plastic substrate was used to design disposable stochastic sensors. Three shapes of nanocoatings were tested. The first shape was obtained by deposition of a nanofilm of Ag on the plastic material; the second shape was obtained by deposition of a composite AgC nanolayer on the plastic material; the third shape was obtained by nanolayer deposition of a composite material of AgC on the top of the Ag nanofilm deposited on the plastic material. α-Cyclodextrin was used to modify the active surface of the sensor. Wide linear concentration ranges were obtained as follows: for de-assay of α-amylase in whole blood: 1.00 × 10−7–1.00 × 103 U mL−1 and for the assay of α-amylase in saliva: 1.5 × 10−15–1.5 × 102 U mL−1. α-Amylase was reliably determined from whole blood and saliva samples using the proposed disposable stochastic sensors.

Three stochastic sensors based on modified nanocarbon paste (nC), nanographene paste (nGr), and reduced graphene oxide paste (rGOx) with 2, 2-diphenyl-1-picrylhydrazyl (DPPH) were proposed for the pattern recognition of bisphenols A (BPA), F (BPF), and Z (BPZ) in waste water samples. The linear concentration ranges recorded were: for BPA between 1fmol/L and 10μmol/L, for BPF between 10fmol/L and 1μmol/L, and for BPZ between 10fmol/L and 0.1mmol/L. The lowest limits of determination for each bisphenol were as following: 1fmol/L for BPA when the stochastic sensor based on nC was used, 10fmol/L for BPF when the stochastic sensors based on nC, nGr, and rGOx were used, and for BPZ 10gmol/L when the sensor based on nGr was used. The recoveries of the BPA, BPF, and BPZ were higher than 98.00% with relative standard deviation less than 0.20% (N = 10).

Three stochastic sensors based on nanodiamond (nDP) paste modified with α, β, and γ‐cyclodextrin were designed and characterized for pattern recognition of aspartame, acesulfame K and sodium cyclamate in beverages, ketchup, and biological fluids. The linear concentration ranges obtained for acesulfame K (between 1.00×10−10 mol L−1and 1.00×10−3 mol L−1), for aspartame (between 1.00×10−12 mol L−1 and 1.00×10−3 mol L−1) and for sodium cyclamate (between 4.97×10−12 mol L−1 and 4.97×10−3 mol L−1) allow their assay in biological fluids, beverages and ketchup. The lowest limits of quantification were obtained using the stochastic sensor based on γ‐CD/nDP: for acesulfame K 1.00×10−10 mol L−1, for aspartame 1.00×10−12 mol L−1 and for sodium cyclamate 4.97×10−12 mol L−1. All three stochastic sensors revealed very high values of sensitivities. The proposed method was reliable for qualitative and quantitative assay of aspartame, acesulfame K and sodium cyclamate in beverages, ketchup, and in biological fluids such as urine.

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