Successful design and manufacture of electrochemical sensors applied in excipient composition analysis

Excipients analysis plays an important role in drug quality control, avoiding the case that some manufacturers use additional active ingredients without or excessively as prescribed, especially for products of unknown origin. Analysis of the amount of medicinal substances in body fluids (blood, urine) helps to learn about the metabolism of drugs and assess the effects of drugs, as well as the risk of side effects. Especially with narrow resolution drugs, high requirements on drug dosing, the alignment of the number of drugs put into the body as well as determining the number of drugs still in the blood is important in ensuring the safety of patients, especially for children.

With widely used drugs such as analgesics, antibiotics and anti-inflammatories, the possibility of large stains of these products in the aquatic environment has been recently discovered; negatively affecting the balance of the aquatic ecosystem and harming aquatic organisms. Another issue of concern is that the use of irritating additives (e.g. gluten) in high levels can have serious consequences for a large group of patients. Therefore, the groups of analytes selected in this study were the group of commonly used active ingredients: analgesics (paracetamol, ibuprofen), anti-inflammatory drugs (diclofenac), and antibiotics (amoxicillin, sulfamethoxazole).

Basically, the sensor is designed with a layer of material with good conductivity, high electron displacement rate and large operating surface area to enhance the electrochemical signal recorded from oxidation or reduction reactions of pharmaceutical substances. Commonly used materials include metal nanoparticles, oxides, conductive polymers, metallic frameworks (MOFs) or nano carbon (graphene, carbon nanotubes) (Figure 1).

Figure 1. Some electrochemical sensor materials

Through the research process, the team has successfully designed and fabricated a number of suitable material membranes to develop electrochemical sensors applied in the analysis of important active ingredients commonly used in pharmaceuticals such as paracetamol, metroxate, gliadin. The main method of material fabrication is developed on the basis of electrochemical techniques, especially ring scanning.

The manufactured sensor has a compact size (1 * 2cm) suitable for analyzing the active ingredient content in human fluid (blood, urine), analyzing the composition of the finished drug. For samples analyzing the aquatic environment, appropriate changes in the structure of the sensor as well as the sample processing method are required to achieve better analysis efficiency.

Figure 2. Image of the fabricated sensor

The project has developed new electrochemical deposition processes applied in manufacturing a number of important material films applied in electrochemical sensors such as: AuNPs/rGO-PEDOT:PSS, rGO-CNT, rGO/MIP, Cu-BTC. In particular, the processes of deposition of carbon nanomaterials and metals or the formation of MIP films are inherited from the group's previous research. This is the first time the team has approached using electrochemical deposition to create a film with a metallic frame structure like Cu-BTC. Films prepared by electrochemical deposition achieve high uniformity and durability, and there is a significant improvement in electrochemical signals recorded on these films. The success of this research opens up opportunities for us to continue our studies with other complex structures that have great promise for applications in electrochemical sensing.

The project has succeeded in developing sensors for not only active ingredients that are as good as redox as paracetamol, as difficult to oxidize as metroxate, and not as redox as gliadin. Flexibility in sensor configuration design to suit the measuring object is essential. The research team's orientation is to develop sensors to support the effective monitoring of the treatment process of cancer patients and sensors to monitor the effectiveness of treatment using narrow-band drugs in vulnerable patients.

The project has also published 03 scientific articles in international journals on the list of SCIE and 01 article in VAST02 magazine.

Translated by Phuong Ha
Link to Vietnamese version