A new nano-optical sensor thin film cadmium sulfide doped in sol–gel matrix for assessment of α-amylase activity in human saliva

Abstract

A novel, simple, sensitive and precise spectrofluorimetric method is developed for measuring the activity of the α-amylase enzyme in human saliva. The remarkable quenching of the luminescence intensity at 634 nm of nano CdS doped in a sol-gel matrix by various concentrations of maltose (produced from the reaction of the enzyme with the starch substrate) was successfully used as an optical sensor for the assessment of α-amylase activity. The calibration plot was achieved over the concentration range 4.8 × 10(-10) to 1.2 × 10(-5) mol L(-1) maltose with a correlation coefficient of 0.999 and a detection limit of 5.7 × 10(-11) mol L(-1). The method was used satisfactorily for assessment of the α-amylase activity in a number of human saliva samples collected from various healthy volunteers.

Sensitive colorimetric assays for α-glucosidase activity and inhibitor screening based on unmodified gold nanoparticles

“…For acarbose, quercetin and genistein, the concentration is 100 μM, and for gallic acid it is 5 mM, respectively. [47] CdS nanoparticle-sol-gel-thin films [48] 0.022 ~3.8(57 fM) Scheme 1. …”

Preparation and characterization of a novel optical chemical sensor for determination of trace amounts of Praseodymium ion by UV/Vis spectrophotometry

“…Among different factors affecting the outcome of optical sensors, type of polymer matrix has a significant effect [15,16]. Many supporting materials such as PVC [17][18][19] or sol-gel [20,21] can be employed to prepare the optical sensors. In this work, a mesoprous SBA-15 matrix was synthesized by hydrothermal method introduced by Tadjarodi et al [22].…”

Saliva, a Magic Biofluid Available for Multilevel Assessment and a Mirror of General Health—A Systematic Review

“…Lee et al developed a biosensor consisting of molecularly imprinted thin films that, after being tested on saliva from five healthy subjects, proved an accuracy between 93.89% and 95.52% [35]. Another nano-sensor used for salivary amylase was developed by Attia et al The sensors were applied on different starch-containing foods and showed high sensitivity (detection limit of 5.7 × 10 −11 mol/L −1 ) [36].…”