Electronic Supporting Material on the MicrochimicaActapublication entitled

Layered vanadium(IV) disulfide nanosheets as a peroxidase-like nanozyme for colorimetric detection of glucose

Lunjie Huang, aWenxin Zhu, aWentao Zhang, a Kai Chen, aJing Wang, aRong Wang, aQingfeng Yang, aNa Hu, bYouruiSuo b and Jianlong Wang* a

aCollege of Food Science and Engineering, Northwest A&F University,Yangling 712100, Shaanxi, China

bQinghai Key Laboratory of Qinghai-Tibet Plateau Biological Resources, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008, Qinghai, China.

*Corresponding author. Tel./fax: +86 29-8709-2275

E-mail:

Contents:

The optimization of catalytic condition: pH value.

The optimization of catalytic condition: temperature.

The leaching experiment of VS2 POX-mimicking catalyst.

The thermal stability of VS2 POX mimics.

The re-utilization test of VS2 POX-mimicking catalyst.

The fluorescent experiment for probing catalytic mechanism of VS2 POX mimics.

Comparison of the performance of nanozyme-based assays for glucose detection.

Detection of the glucose content in fruit juice samples.

The optimization of catalytic condition: pH value.

Fig. S1.PH-dependent catalytic behavior of VS2 catalysts. Activity of 100% is set where absorbance is highest and the relative activities for others are calculated accordingly. Reaction condition: 40 μg·mL-1 VS2 nanosheets, 20 mM H2O2, and 0.5 mM TMB for 5 min incubation at room temperature.

As shown, there is no significant difference in catalytic activity of VS2 POX mimics when incubated with TMB at pH 3 or pH 4. In this study, a relatively mild condition (pH value of 4) is chosen for the catalytic reaction.

The optimization of catalytic condition: temperature.

Fig. S2.Temperature-dependent catalytic behavior of VS2 catalysts. Activity of 100% is set where absorbance is highest and the relative activities for others are calculated accordingly. Reaction condition: 40 μg·mL-1 VS2 nanosheets, 20 mM H2O2, and 0.5 mM TMB for 5 min incubation at pH 4.

The result indicates thatVS2 can maintain relatively high catalytic activity (> 50%) in a wide range of temperature (4–70 °C) with a highest activity at 45 °C.However, the catalyst also exhibits well at 25 °C, with over 80% catalytic activity.More importantly, temperature condition at 25 °C is commonly-accepted as room temperature condition, which is advantageous and convenient for following investigations.In this study, a relatively common condition (temperature at25 °C) is chosen for the catalytic reaction.

The leaching experiment of VS2 POX-mimicking catalyst.

Fig. S3. The leaching solution is the supernatant obtained through centrifugation (12000 rpm (7727 rcf) for 30 min) of 100 μg·mL-1 VS2 storage solution. The blank control is the mixture solution of H2O2 and TMB. Condition: 20 mM H2O2 and 0.5 mM TMB in acetate buffer (pH 4.0) at room temperature.

The thermal stability of VS2 POX mimics.

Fig. S4. The thermal stability of VS2POX mimics under the heating treatment at 60, 80, and 100 °C. Activity of 100% is set by the absorbance catalyzed by untreated VS2 and the relative activities for others are calculated accordingly.The data was obtained throughmonitoringthe spectra of the mixture solution of H2O2 and TMB under the catalysis ofthe treated VS2(50μg·mL-1). Condition: 20 mM H2O2 and 0.5 mM TMB in acetate buffer (pH 4.0) at room temperature.

The re-utilization test of VS2 POX-mimicking catalyst.

Fig. S5.Catalytic activity of VS2nanosheets over various cycles of re-utilization under identical reaction conditions.Activity of 100% is set where absorbance is highest and the relative activities for others are calculated accordingly. The re-utilization of the catalyst wascarried out using a scale-up reaction system. The catalyst was recycled bycentrifugation (12 000 rpm (7727 rcf) for 30 min) and washed with deionized water before re-dispersion. Reaction condition: 1 mg VS2 catalyst (with a final concentration of 50 μg·mL-1), 0.5 mM of TMB,and 20 mM H2O2in acetate buffer (pH 4.0) for 5 min incubation per cycle.

The fluorescent experiment for probing catalytic mechanism of VS2 POX mimics.

Fig. S6. The PL spectra of the 2-hydroxy terephthalic acid under the catalysis of (a)no catalyst, (b) 25μg·mL-1, (c) 50 μg·mL-1of VS2nanosheetsin the coexistence of 10 mMH2O2. Condition: 0.25mM terephthalic acidin acetate buffer (pH 4.0), at room temperature. The excitation wavelength is 315 nm.

Table S1. Comparison of the performance of nanozyme-based assays for glucose detection.

Catalyst / Linear range
(μM) / Detection limit (μM) / Reference
VS2 NSs / 5-250 / 1.54 / This work
BSA-Cu NCs / 100-2000 / 100 / [1]
Pt NPs / 1-50 / 1 / [2]
Fe3O4 NPs / 50-1000 / 30 / [3]
Co3O4 NPs / 10 -10000 / 5 / [4]
NiCo2O4 / 100-4500 / 5.31 / [5]
GO-COOH / 1-20 / 1 / [6]
g-C3N4 / 5-100 / 1 / [7]
WS2 NSs / 5-300 / 2.9 / [8]
MoS2 NSs / 5-150 / 1.2 / [9]
CuZnFeS NCs / 16-60 / 6.1 / [10]
Co3O4@CeO2 / 1-75 / 1.9 / [11]
Cu-Ag/rGO / 1-30 / 3.82 / [12]
P-LaNiO3 NCs / 10-50 / 8.16 / [13]

Table S2. Detection of the glucose content in fruit juice samples.

Sample / Glucose assay kit (mM)a / Glucose spiked (μM)b / Diluted 100 times
(μM) / Glucose measured (μM) / Recovery
(%) / RSD
(n = 3 ; %)
Apple juice sample 1 / 12.39 / 0 / 123.9 / 120.86 / 97.55 / 2.76
Apple juice sample 2 / 17.39 / 50 / 173.9 / 174.28 / 100.22 / 3.10
Orange juice sample 1 / 13.87 / 0 / 138.7 / 140.12 / 101.02 / 1.55
Orange juice sample 2 / 14.87 / 10 / 148.7 / 146.96 / 98.83 / 2.90

aThe glucose determination was performed directly by a Glucose (HK) Assay Kit (Sigma Aldrich).

bTheexogenous glucose was added into the juice samples before dilution, and "glucose spiked"represented the glucose content added after dilution.

Reference

[1] Hu L, Yuan Y, Zhang L, Zhao J, Majeed S, Xu G (2013) Copper nanoclusters as peroxidase mimetics and their applications to H2O2 and glucose detection. Anal ChimActa 762:83-86

[2] Ju Y, Kim J (2015) Dendrimer-encapsulated Pt nanoparticles with peroxidase-mimetic activity as biocatalytic labels for sensitive colorimetric analyses. Chem Commun 51(72):13752-13755

[3] Wei H, Wang E (2008) Fe3O4 magnetic nanoparticles as peroxidase mimetics and their applications in H2O2 and glucose detection. Anal Chem 80(6):2250-2254

[4] Mu J, Wang Y, Zhao M, Zhang L (2012) Intrinsic peroxidase-like activity and catalase-like activity of Co3O4 nanoparticles. Chem Commun 48(19):2540-2542

[5] Huang W, Lin T, Cao Y, Lai X, Peng J, Tu J (2017) Hierarchical NiCo2O4hollow sphere as a peroxidase mimetic for colorimetric detection of H2O2 and glucose. Sensors 17(1):217

[6] Song Y, Qu K, Zhao C, Ren J, Qu X (2010) Graphene oxide: intrinsic peroxidase catalytic activity and its application to glucose detection. Adv Mater 22(19):2206-2210

[7] Lin T, Zhong L, Wang J, Guo L, Wu H, Guo Q, Fu F, Chen G (2014) Graphite-like carbon nitrides as peroxidase mimetics and their applications to glucose detection. BiosensBioelectron 59:89-93

[8] Lin T, Zhong L, Song Z, Guo L, Wu H, Guo Q, Chen Y, Fu F, Chen G (2014) Visual detection of blood glucose based on peroxidase-like activity of WS2 nanosheets. Biosens Bioelectron 62:302-307

[9] Lin T, Zhong L, Guo L, Fu F, Chen G (2014) Seeing diabetes: visual detection of glucose based on the intrinsic peroxidase-like activity of MoS2 nanosheets. Nanoscale 6(20):11856-11862

[10] Dalui A, Pradhan B, Thupakula U, Khan A H, Kumar G S, Ghosh T, Satpati B, Acharya S (2015) Insight into the mechanism revealing the peroxidase mimetic catalytic activity of quaternary CuZnFeS nanocrystals: colorimetric biosensing of hydrogen peroxide and glucose. Nanoscale 7(19):9062-9074

[11] Jampaiah D, Reddy T S, Coyle V E, Nafady A, Bhargava S K (2017) Co3O4@ CeO2 hybrid flower-like microspheres: a strong synergistic peroxidase-mimicking artificial enzyme with high sensitivity for glucose detection. J Mater Chem B 5(4):720-730

[12] Darabdhara G, Sharma B, Das M R, Boukherroub R, Szunerits S (2017) Cu-Ag bimetallic nanoparticles on reduced graphene oxide nanosheets as peroxidase mimic for glucose and ascorbic acid detection. Sensors Actuat B Chem238:842-851

[13] Wang X, Cao W, Qin L, Lin T, Chen W, Lin S, Yao J, Zhao X, Zhou M, Hang C (2017) Boosting the Peroxidase-Like Activity of Nanostructured Nickel by Inducing Its 3+ Oxidation State in LaNiO3 Perovskite and Its Application for Biomedical Assays. Theranostics 7(8):2277-2286

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