Figure 12.

Number of publications on ion/molecule sensors based on 2D materials and metal oxides by years. The data were collected using the Web of Science [v. 5. 32]–Web of Science Core Collection Search: keywords of ((“hydrogen ion” OR glucose OR Pd²⁺ OR Sr²⁺ OR Cu²⁺ OR Cd²⁺ OR Hg²⁺ OR Pb²⁺ OR Cr⁴⁺ OR Ni²⁺ OR Co²⁺ OR Mn²⁺ OR uric OR ascorbic OR dopamine OR DNA OR amino OR protein sens*) AND (graphene OR MoS₂ OR molybdenum disulfide OR black phosphorous OR MoSe₂ OR molybdenum selenide OR WS₂ OR tungsten disulfide OR WSe₂ OR tungsten diselenide)) and ((“hydrogen ion” OR glucose OR Pd²⁺ OR Sr²⁺ OR Cu²⁺ OR Cd²⁺ OR Hg²⁺ OR Pb²⁺ OR Cr⁴⁺ OR Ni²⁺ OR Co²⁺ OR Mn²⁺ OR uric OR ascorbic OR dopamine OR DNA OR amino OR protein sens*) AND (oxide)) were used.