The quantities of aluminum (Al, Cadmium (Cd), nickel (Ni) and tin (Sn) were estimated in twenty samples of packaged dates imported from the Middle East and North Africa countries collected from the Malaysian markets in Selangor - West Malaysia. The varieties include, Ajwa, Deglet Nour, Lulu, Mariami, Zahdi (two samples from different suppliers), Medjool, Mabroom, Khudri, Lamri, two unidentified species under trade marks ( nomades standard, palm dates), Safawi ( two samples from different suppliers), Khasouei, Khalas-Ihsa, fard, Roshdi, Mashrook and Rabbi .20 g of each sample was washed with 15 mL of deionized distilled water for 90 second. Washing residues and washed date tissues were dried and digested by mixture of nitric acid and hydrogen peroxide (15:20). The effectiveness of water washing on the removal of residues of heavy elements accumulated on dates was measured by comparing the contents in both washing residues and date tissue after washing. where the effectiveness ranged from 9.35 to 34% of the total content according to type of element. The study concluded that washing dates before direct consumption or manufacturing can play an important role in the removing some of the contents of heavy elements and reduces the health risk that can be caused to the consumer.

Over the last decade, researchers have paid more attention to gold nanoparticles (AuNPs) due to their unique optical properties that can be used for a nanosensor platform based on colorimetry and fluorescence detection. AuNPs are developed via functionalization as a sensing element based on colorimetric or fluorimetric detection for the target analyte, such as metal ions in water samples. In this chapter, we have focused on novelties of the functionalized AuNPs as sensors for Al3 + ion detection. The novel sensing approaches were discussed using functionalized AuNPs to enhance the possibility of developing nanosensors for detection of Al3 + ions that exhibit desirable characteristics, such as high sensitivity, selectivity, rapid, and simple. The recent advantages of functionalized AuNPs that highlight the reliability of their applications for detection of trace Al3 + ions in water samples are evaluated.