Trace Detection of Ciprofloxacin in Milk by Label-Free Raman Enhancement using Two-Dimensional Magnesiochromite

Abstract

Antibiotic resistance and adverse reactions in humans can be avoided by detecting antibiotics early in the milk supply chain. To meet the demand, we developed a flexible and simple optical sensing method based on a non-van der Waals two-dimensional (2D) metal oxide, 2D-magnesiochromite (2D-MgCr2O4). We used a rapid, label-free Raman enhancement mechanism for antibiotic detection. The Raman spectral mapping method has also been used to quickly identify traces of antibiotics in food products. Here, we have used UV–visible spectroscopy, Raman spectroscopy, and Raman imaging to analyze the 2D material’s detection potential in water initially and finally in milk. The device has over a month-long shelf life, even when stored in typical atmospheric conditions, and the acquired detection limits are 30 ng/mL by UV–visible spectroscopy and 10 ng/mL by Raman spectroscopy in milk. Such methods can be extended to detection of other toxic ingredients in food products.

Subpicomolar Dopamine Detection Using Two-Dimensional Cobalt Telluride

“…The thickness of the 2D flakes can be determined by the AFM images obtained from Figure d. Based on the histogram present in the inset, it is evident that the thickness of all flakes falls within the range of 1–10 nm, thereby meeting the requisite criteria for the formation of a 2D structure . Furthermore, it is observed that the majority of the flakes exhibit a thickness ranging from 3 to 5 nm, which confirms the formation of few-layered 2D CoTe 2 .…”

3D-printed flexible energy harvesting devices designed using non-layered two-dimensional natural tourmaline silicates

“…For the exfoliated T-silicate, the potential is −30 mV, which suggests a negative charge on the exfoliated sheets. Zeta potentials of graphene, 27 hBN, 28 MoS 2 , 29 2D black phosphorus, 27 2D spinel oxide, 30 and 2D layered silicates such as mica 31 and biotite 32 were compared with those of non-layered 2D T-silicates reported in this work.…”

A comprehensive review of atomically thin silicates and their applications

“…It is evident that 2D silicates have higher stiffness values [45] than black phosphorus [46], silicene [47], and WSe 2 but lower than MoS 2 [48], graphene [49], and hBN [50]. The zeta potential values (stability in suspension and charge) are negative for 2D silicates [51,52] and larger than the corresponding values for the majority of 2D materials [53][54][55][56], as shown in figure 2(d). The magnetic property chart in figure 2(e) indicates that natural silicates in 2D configurations are predominantly paramagnetic, but ferromagnetic (FM) behavior is possible if combined with appropriate elements [57].…”