Furthermore, this electrode has multiple layers on top permitting repeated uses after washing, these layers also provide significant durability and resistances against interferential substances in the solutions as described in previous studies [6] and [7]. Fig. 4(a) represents the comparisons between the amperometric responses on the first day of measurements and those after 30 days with the same chips. The chips were stored in a fridge when not being used. Compared with our previous study using FGO-Au-PCB chips without multiple layers [13], the overall level of measured current increased by 20 times as well as the long term stability

was increased up to 5.6%. It was demonstrated that current generated by the multiple layer-Au-PCB http://www.selleckchem.com/products/OSI-906.html drops

to overall 8.7% of its initial value within 30 days. The resistant ability of the Au-PCB electrode modified with multiple layers was investigated under additions of different interferential substances, such as ascorbic acid, uric acid, acetaminophen, XL184 supplier creatinine and all these substances mixed together (Fig. 4(b)). The Au-PCB chip exhibited no variations with the increases of the added interferential substances, indicating that the layers on top of the electrode efficiently restrict those substances from penetrating them to reach the electrode which explains the increase of current level as well as long term stability of our fabricated chips. In addition, no changes were also observed when the inferential substances were added both in time and concentration dependent manners. The amperometric response in urine was measured from the patients (n = 30) with hyperglycemia and their patterns of responses were compared with the concentration of glucose in blood measured with a commercially available glucose meter. As can be seen in Fig. 5(a), the amperometric

responses from a single chip, which are represented by black solid circle and left Y axis, have a similar pattern to the measured blood glucose (red solid square and right Y axis) suggesting that our selleck compound system is able to measure the level of glucose in an accurate manner as well as being stable during multiple uses in real samples. Fig. 5(b) shows the high correlation between blood glucose and glucose in urine with squared R of 0.91, which means the amount of glucose in blood is likely to be linearly correlated with the concentration of glucose in urine. In summary, we fabricated functionalized graphene oxide, which is an integration of metalloid polymer hybrids with oxidized graphene oxide nanosheets. Functionalized graphene oxide was then adsorbed on gold electrodes to form a FGO-Au-electrode. The FGO-Au-electrode chips with multiple layers were prepared by spin coating to form a multilayer-FGO-Au-electrode and then each of them was implemented on the PCBs.