Beryllium hexaaluminate-MXene-employed SPR sensor for detecting heavy metal ions in drinking water

Contamination of surface or ground waters with heavy metals is a major risk factor both for public health and the environment. Thus, it is necessary to develop fast, accurate, and label-free detection methods. In this research, a computational SPR study using a novel BK7 prism/silver (Ag)/beryllium hexaaluminate (BeAl[Formula: see text]O[Formula: see text]), abbreviated as BHA/MXene, design was conducted to investigate numerically the use of an optical sensor based on surface plasmon resonance (SPR) to detect various concentrations of heavy metal ions in aqueous media. The analytical performance of the proposed biosensors was studied using the transfer matrix method (TMM) as a function of the variation of the resonance angle that occurs due to the changes in the refractive index (RI) of the solution resulting from the presence of mercury (II) [Hg(II)], lead (II) [Pb(II)] nickel (II) [Ni(II)], zinc (II) [Zn(II)], and copper (II) [Cu(II)]. For comparison purposes, drinking water (with an RI of 1.3317) has been assumed as the reference medium. The maximum value of the sensitivity was found to be 210.26 ∘ /RIU for Hg(II), whereas Pb(II) produced the highest angular shift ([Formula: see text]). In addition to sensitivity, the full-width at half maximum (FWHM) also appeared to remain relatively constant at values between 4.69 ∘ and 4.73 ∘ , which indicated that the resonance properties were very stable across all of the investigated analytes. Additionally, the sensor displayed a maximum detection accuracy (DA) of up to 0.2132[Formula: see text] and a figure of merit (FoM) of 44.509 RIU[Formula: see text] for Zn (II). Overall, these results have demonstrated that the proposed SPR-based sensor can accurately distinguish between the various forms of heavy metal ions with a high degree of sensitivity and good detection performance. Thus, it represents a suitable model system for real-time detection of contaminants in the environment and portable detection of heavy metals.