Multilevel, Dual-Readout Logic Operations Based on pH-Responsive Holmium(III)-Doped Carbon Nanodots

Abstract

The increasing demand for large-scale integrated logic systems urges the development of multireadout molecular logic gates. Especially, it is of great significance to explore dualreadout logic devices with both fluorescence (FL) and magnetic resonance (MR) signals as measurable outputs, since the signal combination of FL/MR might render molecular logic devices better practicality in biomedical applications. In this study, holmium(III)-doped carbon nanodots (Ho-CDs), which exhibited pH-responsive behaviors in both FL and MR signals, were synthesized by a facile one-pot pyrolysis method. When triggered by H + , Fe 3+ , or Fe 2+ , the Ho-CDs served as a switch for both FL and MR signals, leading to dual-readout and multiaddressable logic gates. A series of elementary Boolean operations including YES, NOT, OR, NOR, XOR, PASS 0, and INH have been successfully demonstrated by varying the chemical inputs of H + /Fe 3+ /Fe 2+ . More importantly, multilevel integrative Boolean operations with higher functions (NOR−INH and MR (XOR + INH)−OR), which realize the concatenation of different logic gates, have also been successfully demonstrated. This study may pave an avenue to design multilevel, dual-readout molecular logic systems with better operation stability, which hold great potential for biomedical applications in the future.

Carbon Dots for Multiuse Platform: Intracellular pH Sensing and Complementary Intensified T1–T2 Dual Imaging Contrast Nanoprobes

“…For instance, Fang et al prepared Ho-doped carbon quantum dots as a positive contrast enhancement agent with quite a low value of longitudinal relaxivity (r1), which was 0.1128 mM –1 s –1 . In 2020, Fang et al manufactured Ho-doped carbon nanodots for dual mode fluorescence and magnetic resonance imaging purposes, where Ho-CQDs showed enhancement in T1 weighted images with an r1 value of 2.049 mM –1 s –1 , which is quite low in comparison with our Ho–Mn–CQDs …”

Carbon Dots-Based Logic Gates

“…Cr 6+ sensing and antibacterial activity AND Single [67] N-doped CDs Hg 2+ and glutathione detection, cell imaging IMP Single [49] Polyethyleneimine-capped fluorescent CDs Cu 2+ and H 2 S detection INHIBIT Single [43] CDs-gold nanoparticle Detection of pesticides INHIBIT-OR Combination [25] Nitrogen-doped CDs Cu 2+ and GSH detection AND Single [39] Nitrogen-doped CDs chlorpromazine hydrochloride detection AND Single [70] Pristine CDs Fe 3+ anf Fsensing AND Single [40] Holium doped CDs dual imaging XOR+INH-OR Integrative [58] 6. Future Perspectives…”

“…The chemical inputs were H + , Fe 3+, and Fe 2+ , while the fluorescence output was recorded at 440 nm along with magnetic intensity. A fluorescence-based NOR-INHIBIT and MR-based (XOR-INHIBIT)-OR sequential logic system was demonstrated successfully [ 58 ].…”

“…Yi et al synthesized holmium (Ho 3+ ) doped CDs (Ho-CDs), which exhibited pH responsiveness for both FI and magnetic resonance (MR) signals. In this study, the inputs were H + , Fe 2+ , or Fe 3+ , and the change in FI and MR signals served as an output for multilevel logic operations [ 58 ].…”

Logic Gate Design Using Multicolor Fluorescent Carbon Nanodots for Smartphone-Based Information Extraction

“…Extensive efforts have been made to investigate luminescent mechanisms and establish protocols to synthesize multicolor CDs for bioimaging, chemo-/biosensing, photocatalysis, photovoltaics, etc. − Different functional groups on the CD surface made them suitable candidates for implementing logic operations due to their rapid fluorescence “turn-on” or “turn-off” response to analytes . Actually, CDs with ultrafine dimensions have substantially contributed to developing recognition-based molecular logic gates using fluorescence as the readout signal in recent years. − The logic output can be observed by the change in intensity or wavelength of emission or absorption, establishing the basis of the logic operation via the known Boolean arithmetic function. , Obviously, multicolor CD-based logic gates show great potential for optical sensing, leading to a new detection strategy in the field of molecular diagnosis.…”