Sharif Digital Repository

In this study, biosorption of selenium by Pseudomonas putida bacteria was investigated in both single and binary uptake systems. Bacteria cells were immobilized in the chitosan beads, to study impact of microorganism entrapment on the sorption capacity of the fabricated adsorbent. Uptake capacity increased by the entrapped bacterial weight percent up to 20 wt. %; but thereafter, sorption capacity gradually leveled off with an increase in the loading percentage of the bacterial cells.The effects of the three process variables including pH (2-6), biomass dosage (0.5-2.5 g/L) and initial concentration of selenium (50-250 mg/L) on the uptake performance of adsorbent were investigated, and... 

The demand for rapid and sensitive multi-analyte detection of dopaminergic agents in assessing the progression of Parkinson’s disease (PD) has attracted recurring interest in recent years. In this study, a multicolor sensor was devised to multiplex detection and discrimination of levodopa (L-DOPA), carbidopa (Carbi), and benserazide (Benz)—key dopaminergic compounds. Notably, the presence of dopaminergic agents inhibits the etching of gold nanorods (AuNRs) by N-bromosuccinimide (NBS), with varying degrees of inhibition depending on the concentration and properties of the analytes. This interaction induces alterations in the size and aspect ratio of the AuNRs, resulting in a red shift within...