Nitrogen-Incorporated Ovoid-Shaped Nanodiamond Films for Dopamine Detection

Abstract

Nitrogen-incorporated ovoid-shaped nanodiamond (NOND) film exhibits excellent electrochemical sensing properties owing to its unique characteristics. In this study, to improve the sensitivity of NOND-based biosensors for dopamine (DA) detection, a detailed investigation concerning the growth mechanism of NOND films was conducted, it is found that the NOND films did not directly grow on a Si substrate during the growth process but preferentially originated from the formation of a thin Si3N4 interlayer attributed to the reactions of Si substrate and nitrogen atoms in the plasma in the very early stage of deposition. Subsequently, the diffusion of nitrogen from the inner Si3N4 to the Si3N4/plasma interface produces more active sites for the adsorption of the ionized carbon atoms. As the process proceeded further, the growth of ovoid-shaped diamonds accompanies the decrease of the Si3N4 interlayer thickness owing to the diffusion of nitrogen from Si3N4. Significant Si3N4 peaks are observed from both the Raman and X-ray diffraction analyses when the sample was subjected to NOND deposition for less than 20 min. These peaks then completely disappeared after deposition for 60 min, demonstrating the proposed mechanism. Furthermore, it is also observed that the deposition of the Si3N4 interlayer increased the hydrophilicity of the substrate, which is ascribed to the lower surface free energy of the NOND. To enhance the sensitivity of the NOND, the synthesis of NOND with patterned arrays (P-NOND) is proposed. The high specific surface area of the highly hydrophilic P-NOND obviously enhances the sensitivity of the P-NOND-based electrodes. Application of the P-NOND electrode for DA detection is successfully demonstrated in the mixed DA electrolyte, showing a better performance than that of the pristine NOND. This work reveals that the P-NOND electrode possesses superior sensitivity and selectivity, which is very favorable for DA sensing.

Recent Development of Nano-Carbon Material in Pharmaceutical Application: A Review

“…Various approaches have been utilized to overcome this issue. For example, Chang et al, (2020) [ 133 ] develop electrochemical sensor using nitrogen-incorporated ovoid-shaped nanodiamond (NOND). The NOND film was synthesized using MPECVD method in pristine and patterned Si substrate.…”

Bottom–Up Evolution of Diamond–Graphite Hybrid Two‐Dimensional Nanostructure: Underlying Picture and Electrochemical Activity

“…Such excellence was particularly pronounced for the AA detection performance. Note that none of the previous form of diamond film, neither the porous/nonporous boron-doped diamond (BDD) film [64][65][66] nor the N-incorporated diamond film [4,26] were able to detect the AA molecule.…”

“…[14] The N-UNCD is fabricated through the intriguing bottom-up evolution of the diamond-graphite hybrid nanostructure under chemical vapor deposition (CVD). [4][5][6][7][8][9] While the material is indeed outstanding in the neural stimulation and recording, there's still an important issue to be resolved: their performance for the simultaneous electrochemical detection of the neural transmitter, for example, dopamine (DA) in presence of ascorbic acid (AA) and uric acid (UA) is still far from satisfactory, [26,27] as compared to that of the nanocarbon-powder-based porous thin films. [28] Furthermore, the detection of AA in presence of interference from DA and UA, which is inevitable in many biological samples, [29] is particularly challenging, relative to those of DA and UA, which might be attributed to the lack of π-π molecular bonding route of AA absorption on carbon electrode.…”

Human Exhalation CO2 Sensor Based on the PEI-PEG/ZnO/NUNCD/Si Heterojunction Electrode

“… 31 , 32 In particular, nitrogen-incorporated diamond films can increase the formation of sp 2 hybridization, which is beneficial in increasing the number of charge carriers. 33 NUNCDs have been used in several applications, especially in biosensors; 34 − 36 in this regard, the sensing surface area and the electrical conductivity are two key parameters to affect the sensor performance. A heterojunction semiconductor system can create more electron travel pathways due to the generation of electric fields at the interfaces.…”

“…According to the published articles, it was reported that the incorporation of N 2 into the CH 4 plasma in the UNCD fabrication process can synthesize electrically active acicular-shaped NUNCD which possesses excellent charge transmission properties with high surface area. , In particular, nitrogen-incorporated diamond films can increase the formation of sp 2 hybridization, which is beneficial in increasing the number of charge carriers . NUNCDs have been used in several applications, especially in biosensors; − in this regard, the sensing surface area and the electrical conductivity are two key parameters to affect the sensor performance. A heterojunction semiconductor system can create more electron travel pathways due to the generation of electric fields at the interfaces. − NUNCD and ZnO/NUNCD on the Si substrate possess different work functions; the lower work function of ZnO/NUNCD facilitates carrier transfer through the interfaces.…”