Achmann S, Hermann M, Hilbrig F, Jérôme V, Hämmerle M, Freitag R, Moos R
Chair of Functional Materials, University of Bayreuth, 95440 Bayreuth, Germany.
Talanta. 2008 May 15;75(3):786-91. doi: 10.1016/j.talanta.2007.12.015. Epub 2007 Dec 23.
An amperometric enzyme-based sensor-system for the direct detection of formaldehyde in air is under investigation. The biosensor is based on a native bacterial NAD(+)- and glutathione-independent formaldehyde dehydrogenase as biorecognition element. The enzyme was isolated from Hyphomicrobium zavarzinii strain ZV 580, grown on methylamine hydrochloride in a fed-batch process. The sensor depends on the enzymatic conversion of the analyte to formic acid. Released electrons are detected in an amperometric measurement at 0.2V vs. Ag/AgCl reference electrode by means of a redox-mediator. To optimize the sensing device, Ca(2+) and pyrroloquinoline quinone (PQQ) were added to the buffer solution as reconstitutional substances. At this stage, the sensor shows linear response in the tested ppm-range with a sensitivity of 0.39 microA/ppm. The signal is highly reproducible with respect to sensitivity and base line signal. Reproducibility of sensitivity is more than 90% within the same bacterial batch and even when enzyme of different bacterial batches is used.
一种用于直接检测空气中甲醛的基于安培法的酶传感器系统正在研究中。该生物传感器基于一种天然的细菌NAD(+)和谷胱甘肽非依赖性甲醛脱氢酶作为生物识别元件。该酶是从在分批补料过程中以盐酸甲胺为培养基生长的扎瓦尔齐尼生丝微菌ZV 580菌株中分离出来的。该传感器依赖于分析物向甲酸的酶促转化。通过氧化还原介质在相对于Ag/AgCl参比电极0.2V的安培测量中检测释放的电子。为了优化传感装置，将Ca(2+)和吡咯并喹啉醌(PQQ)作为重构物质添加到缓冲溶液中。在此阶段，该传感器在测试的ppm范围内显示出线性响应，灵敏度为0.39 μA/ppm。该信号在灵敏度和基线信号方面具有高度的可重复性。在同一批细菌内，甚至使用不同批细菌的酶时，灵敏度的重现性超过90%。
