纳米金电催化传感器系统用于果蔬乙烯监测和控制

Nanoporous Gold Electrocatalysis for Ethylene Monitoring and Control

纳米金电催化传感器系统用于果蔬乙烯监测和控制

R. Shekarriz，W. L. Allen

Summary:

Maintaining the quality and freshness of fruit and vegetables during transportation and storage is an important role for most postharvest industries. One way to
control freshness is by carefully monitoring and regulating exposure to ethylene. By limiting exposure to ethylene the natural aging process of fresh produce is slowed down, thus prolonging its shelf life. This is especially important for organic produce where the use of chemicals for decay control is not practiced. In this
paper, the performance characteristics and method of use of a new sensing approach for postharvest ethylene measurements is introduced. In this sensor,ETH-1010, oxidation of ethylene on a gold electrocatalyst produces a highly detectable and measurable amperometric signal. ETH-1010 has been packaged into a complete field portable unit. It continuously samples the air at a set flow rate, (commonly between 200 and 500 ml min–1), and reports the ethylene concentration in air at a user-specified time interval. The direct contact between the ethylene molecules in air and electrocatalytic surface renders this process more sensitive and responsive than conventional diffusion-type electrochemical cells. This approach has been shown to be quite effective for continuous monitoring of cold storage rooms, where detection of lower than 10 ppm down to 10 ppb is desirable. This configuration was also used to examine the applicability of electrocatalysis for scrubbing ethylene. Results for ethylene removal have been presented in this paper where the surface reactivity on the electrocatalyst is typically between 0.1 and 0.2 μmol h–1 cm–2. In the sensor, the high reaction rate provides high sensitivity and response time, while making it feasible to consider using electrocatalysis in a scrubbing mode for future applications.

在运输和储存过程中，保持水果和蔬菜的质量和新鲜度是大多数收获后工业的重要作用。单程到通过仔细监测和调节乙烯暴露来控制新鲜度。通过限制暴露在乙烯中，新鲜农产品的自然老化过程减慢，从而延长其保质期。这对于有机产品尤其重要，因为在有机产品中不使用化学物质来控制衰变。在这个里面

本文介绍了一种新的乙烯采后测定传感方法的性能特点和使用方法。在这个传感器中，ETH-1010，在金电催化剂上氧化乙烯产生一个高度可检测和测量的电流信号。ETH-1010已经包装成一个完整的现场便携式装置。它以设定的流速(通常在200到500毫升的小-1)连续采样空气，并以用户的时间间隔报告空气中的乙烯浓度。空气中乙烯分子与电催化表面的直接接触使该过程比传统的扩散型电化学细胞更灵敏和反应灵敏。这种方法已被证明是非常有效的连续监测冷藏室，其中检测低于10 ppm至10 ppb是可取的。这种结构也被用来检查电催化清洗乙烯的适用性。本文介绍了电催化剂表面活性一般在0.1～0.2μmol h～1cm～2之间的乙烯脱除结果。在传感器中，高反应速率提供了高灵敏度和响应时间，同时使在未来的应用中考虑以擦洗模式使用电催化成为可能。