Nanozymes or nanoparticles with excellent enzyme-like activity are attracted many attention due to their stability and higher efficiency compared to natural enzymes [
1,
2,
3,
4,
5,
6,
7]. In fact, Natural enzymes show several disadvantages such as low stability (thermal and narrow pH range) [
8]. For overcoming these drawbacks, the enzyme immobilization process has been developed [
9,
10,
11,
12,
13]. The recent progresses on nanochemistry and material science open a new door for developing high performance nano-supports such as MOFs, catalytic materials, and nanoparticles with enzyme-like activity [
14,
15,
16,
17,
18,
19,
20]. Several of the above-mentioned nanoparticles reveal high peroxidase-like activity which can be used instead of enzymes in the reactions. Recently, the nanozymes had been used for different applications for instance, analytical sensing of species, biocatalysis of reactions instead of natural enzymes, water treatment, dye degradation, sensing and detection [
21,
22,
23,
24]. Since nanozymes are able to catalyze the oxidation of peroxidase substrates to their corresponding colored products, they have been used for the analytical purposes [
1,
2,
3,
4,
5,
6,
7]. Usually 3,3',5,5'-tetramethylbenzidine (TMB) and 3,3'-diaminobenzidine (DAB) substrates have been used as the peroxidase substrates and their corresponding oxidation products were utilized as the analytical probes for sensing aims [
1,
2,
3,
4,
5,
6,
7]. Silver nanoparticles are well-known as the nanomaterials with -peroxidase-like materials [
25,
26,
27,
28,
29,
30]. In this contribution, the effect of incubation time on nanozyme-catalyzed oxidation of 3,3’,5,5’-tetramethylbenzidine over silver nanoparticles due to importance of the reaction time on producing the corresponding radicals. The process of the oxidation reaction was probed by recording the absorbance of the colored products using UV-Vis spectrophotometer. Herein, the influence of reaction time on silver nanoparticles-catalyzed oxidation of 3,3’,5,5’-tetramethylbenzidine (TMB) was evaluated via probing the oxidation process by recording the UV-Visible absorbance of the resulting colored products of TMB oxidation by hydrogen peroxide in the presence of silver nanoparticles as peroxides mimics. The results of this work revealed that the concentration of the oxidation product was increased by increasing the reaction time and then levled off because the nanozyme active nodes were saturated after a certain reaction time and consequently the steady-state condition can be observed.