In situ attachment of cupric oxide nanoparticles to mesoporous carbons for sensitive amperometric non-enzymatic sensing of glucose

Mesoporous Materials‐Based Electrochemical Sensors

“…Among parameters that are likely to induce loss in sensitivity of mesoporous materials‐based electrocatalytic sensors, one can mention the leaching of the mediator, the loss of poisoning of the supported catalyst, the degradation of the mesostructure host, or the electrode fouling. Some illustrative data are given afterwards for various mesoporous modifiers, as expressed in % decrease in the response observed after selected storage duration: for mesoporous silica: 2.5 % after10 days 168, 6 % after 1 month 192; for mesoporous metal oxides: 8 % after 5 days & 10 % after 10 days 243; for OMC: 10 % after 1 month 226, 7.8 % after 45 days 222, 5.2 % after 2 weeks 270, 8 % after 2 weeks 217, 11 % after 4 weeks 204, or 2/7/14/17 % respectively after 1/2/3/4 weeks 223. From these data, it remains however almost impossible to express accurately the origin of the response drop as it can be due to different parts of such multicomponent composite electrodes, and almost no relevant information on that point can be found in the available published works.…”

“…An intrinsic feature of OMC, which is advantageous over mesoporous silica for instance, is its electrical conductivity, enabling surface modification by electrochemical methods. A first one is the generation of metal nanoparticles, NPs (e.g., Au 166, 208, Pt 209–213, Ag 214, 215, Pd 216, 217, or bimetallic PtPd 218) by cathodic reduction of metal precursors that has been previously impregnated onto OMC (Figure 6 c); note that these NPs (or deposits) can be also directly accommodated to the OMC material by casting from a solution/suspension (Figure 6 c), as especially applied to deposition of metal oxides or sulfides (e.g., Ni(OH) 2 or NiO 219, 220, CuO 221–223, Co 3 O 4 224, Fe 3 O 4 225, CeO 2 226, or Cu 2 S 227). Cu NPs were also deposited onto mesoporous polyaniline 228.…”

“…A second strategy is to deposit the mesoporous particles onto the surface of a solid electrode (Figure 7 B). This can be performed by simple dropping of a suspension containing the powdered material and let the solvent to evaporate (under quiescent or spinning conditions) to get the particulate film onto the electrode surface (see part a of Figure 7 B), as exemplified for mesoporous silica 167, 168, 170, 174, 175, 247, 248 and especially OMC 68, 206–208, 214, 221, 223, 230, 232–235, 244, 249–274. Such particulate films can suffer from poor mechanical stability, notably in stirred solutions, so that they were sometimes covered by a polymer film (e.g., mesoporous CuO/Nafion 275, or OMC/Nafion 226, 276 see part b of Figure 7 B).…”

“…Mesoporous materials by themselves (metals or alloys 238, 312, 315, metal oxides (i.e., CuO 275) or OMC (i.e., CMK‐3 262) can serve for that purpose, but detection requires the use of rather strong alkaline media. Extending linear ranges and lower detection limits can be reached using OMC decorated with metal oxide NPs (e.g., CuO 223 or NiO 220) but these sensors still operated at very high pH values (>12). The most promising systems to date are OMC bearing metal NPs (such as Pt 209, 210 or PtPd 218) as they enable the direct electrocatalytic detection of glucose at low overpotentials in media close to neutrality (e.g., physiological pH).…”

A highly sensitive nonenzymatic glucose sensor based on CuO nanoparticles decorated carbon spheres

“…A c c e p t e d M a n u s c r i p t 8 [17][18][19], grapheme [20], mesoporous carbons [21], and carbon nanofibers [22]) were used as support matrices for CuONPs to enhance the charge transfer.…”