Abstract

Non-enzymatic colorimetric based sensors are rapidly emerging sets of sensors. In this study, cellulose-Ag–Cu nanohybrids were designed to sense urea based on the change in absorbance obtained after the nanohybrid and urea contact. The cellulose-Ag–Cu nanohybrids were characterized with FTIR, SEM, XRD and BET. The bands at 1120, 680 and 620 cm⁻¹ represents the C–O–C of the biopolymer glycosidic linkage, the Ag–O and Cu–O bands while the SEM shows well dispersed nanoparticles with less agglomeration on the cellulosic rods. Braggs diffraction peaks emerged at 2θ angles of 18, 38, 44, 64.5 and 79° for the cellulose-Ag–Cu nanohybrid corresponding to the crystalline domain of the cellulose and 111, 200, 220, 222 face centred cubic crystal planes of silver and copper respectively while the BET gave the value of 162.465 as the nanohybrid surface area. The curve of colorimetric concentration versus the prepared urea concentration was fitted on Boltzmann model and a general equation was constructed for the sensing. The limit of detection of the nanohybrid corresponds to 0.8102 ppm urea concentration. The change in absorbance of the nanohybrid increases as the urea concentration increases but decreases as pH increases. The effect of salts was also evaluated and the change in absorbance increases due to indirect oxidation.

Graphic Abstract

中文翻译：

---

基于比色法的聚山梨酯交联纤维素-Ag-Cu纳米混合传感器，用于尿素传感应用

摘要

基于非酶比色法的传感器是迅速出现的传感器组。在这项研究中，纤维素-Ag-Cu纳米杂化物被设计为根据纳米杂化物和尿素接触后获得的吸光度变化来检测尿素。用FTIR，SEM，XRD和BET对纤维素-Ag-Cu纳米杂化物进行了表征。1120、680和620 cm ^-1处的谱带代表生物聚合物糖苷键，Ag-O和Cu-O谱带的C-OC，而SEM显示纤维素棒上的纳米颗粒分散得很好，没有团聚。纤维素-Ag-Cu纳米杂化物的2θ角分别为18、38、44、64.5和79°，出现了布拉格衍射峰，与纤维素的晶畴相对应，并且银，铝和111、200、220、222面心立方晶面分别以铜和铜作为纳米杂化表面积，而BET的值为162.465。将比色浓度对制备的尿素浓度的曲线拟合在Boltzmann模型上，并建立了用于感测的通用方程。纳米杂化物的检测极限对应于0.8102 ppm的尿素浓度。纳米杂化物的吸光度变化随尿素浓度的增加而增加，但随pH的增加而减小。还评估了盐的作用，由于间接氧化，吸光度的变化增加。

图形摘要