A highly sensitive and moisture-resistant gas sensor for diabetes diagnosis with Pt@In2O3 nanowires and a molecular sieve for protection

Abstract

Sensitive and selective detection of acetone in human exhaled breath plays an important role in the diagnosis of diabetes. However, obtaining a reliable response to ppb levels of acetone and avoiding cross-sensitivity due to the large amount of moisture in exhaled breath are still great challenges. In this work, a type of acetone sensor with ultrahigh sensitivity and moisture resistance is reported. Electrospun In 2 O 3 nanowires with a controllable Pt core (Pt@In 2 O 3 core-shell nanowires) are designed and prepared as sensitive layers. A mesoporous silica molecular sieve is further integrated as the moisture filter layer. The Pt@In 2 O 3 core-shell nanowire-based sensor exhibits a highly improved response compared with a sensor based on pure In 2 O 3 nanowires due to the probable increase in surface resistance and the introduction of p-n junctions after rational design of the structure. In addition, a good performance in terms of the fast dynamic process, selectivity and long-term stability is also achieved, and the detection limit can be as low as 10 ppb, which is much lower than the concentration level of 1.8 ppm in the exhaled breath of diabetic patients. The influence of the large amount of moisture is greatly weakened by using the molecular sieve as a moisture filter layer, leading to much improved sensitivity in clinical sample detection among healthy and diabetic patients. Based on the optimized composite structure of the Pt@In 2 O 3 core-shell nanowire sensor and moisture filter layer, a simple portable sensing prototype is successfully fabricated. The reported Pt@In 2 O 3 core-shell nanowires and the acetone sensing approach open up a new opportunity for a simple, inexpensive, and noninvasive diagnosis of diabetes.

Catalytic Metal Nanoparticles Embedded in Conductive Metal–Organic Frameworks for Chemiresistors: Highly Active and Conductive Porous Materials

“…These outstanding results confirmed the superiority of metal NPs-loaded C-MOFs, as a highly active material with electrical conductivity, for applications in NO 2 sensors operated at room temperature. Although the stability of M@ Cu 3 (HHTP) 2 against humidity was not demonstrated here due to easy adsorption of H 2 O on Cu 3 (HHTP) 2 at high humidity, we suppose that the introduction of additional catalysts or humidity screening membranes, as previously demonstrated, [57,58] can improve the sensing properties even in humid atmospheres.…”

“…Moreover, the partially oxidized Pd and Pt (PdO and PtO as confirmed with XPS analysis) can further affect the baseline resistance by creating additional junctions. Since the work functions of PdO and PtO x are 7.90 and 5.65 eV, respectively, PtO donates electrons to Cu 3 (HHTP) 2 , whereas PdO deprives Cu 3 (HHTP) 2 of electrons (Figure S5, Supporting Information). Therefore, from these reasons, the baseline resistance of Pt@Cu 3 (HHTP) 2 was much higher than that of Pd@Cu 3 (HHTP) 2 .…”

Nanostructured Metal Oxide-Based Acetone Gas Sensors: A Review

“…Electrospun Pt@In 2 O 3 core-shell composite NWs were prepared for acetone sensing studies [129]. The sensor showed a highly improved response, short response and recovery time of 14 and 16 s, respectively, for 1 ppm of acetone, and high selectivity and stability compared with a sensor based on pristine In 2 O 3 NWs due to the increase in surface resistance and the presence of heterojunctions.…”

A high-performance trace level acetone sensor using an indispensable V4C3Tx MXene

“…Recent years have seen an enormous amount of research highlighting oxygenated volatile organic compounds (OVOCs) owing to their threats to human health and the environment. [1][2][3][4] Among various OVOCs, acetone is one of the most promising research candidates for various industrial and medical applications, not least towards diabetes diagnosis [5][6][7] in human exhaled breath. Clinical analysis has shown that the acetone concentration in the exhaled breath of healthy people is 300-900 ppb, while it will increases to more than 1.8 ppm for diabetic patients.…”